The Experts below are selected from a list of 108 Experts worldwide ranked by ideXlab platform

S.r. Bloom - One of the best experts on this subject based on the ideXlab platform.

  • the role of pancreatico biliary secretions in intestinal adaptation after resection and its relationship to plasma Enteroglucagon
    British Journal of Surgery, 2005
    Co-Authors: M Y T Almukhtar, S.r. Bloom, M A Ghatei, G R Sagor, N A Wright
    Abstract:

    Two groups, each containing 16 male Wistar rats, had either 75 per cent small bowel resection or jejunal transection; 8 animals from each group; had previously been subjected to pancreatico-biliary diversion. All animals were killed 12 days after the operation, plasma Enteroglucagon levels were measured and crypt cell production rate (CCPR) at different sites of the remaining small intestine was measured using a metaphase arrest technique with vincristine. In each of the resected groups there was a significant increase in the CCPR and Enteroglucagon levels compared with the transected groups. Furthermore it was found that the CCPR and Enteroglucagon levels were higher in the resected group without the pancreatico-biliary diversion compared with the resected group with the diversion. This study, although it confirms the importance of pancreatico-biliary secretions in intestinal adaptation, could also indicate that a humoral factor may be important in the control of intestinal cell proliferation. Our findings do not exclude the possibility that Enteroglucagon could be a candidate for such a role.

  • the effect of altered luminal nutrition on cellular proliferation and plasma concentrations of Enteroglucagon and gastrin after small bowel resection in the rat
    British Journal of Surgery, 2005
    Co-Authors: G R Sagor, N A Wright, M A Ghatei, M Y T Almukhtar, S.r. Bloom
    Abstract:

    Luminal nutrition is known to have a trophic effect on small bowel mucosa after intestinal resection. Humoral agents, however, may also contribute to this process. Two of the proposed humoral agents, Enteroglucagon and gastrin, were therefore investigated after intestinal resection and transection in the rat, and changes in their concentration in the plasma were related to cellular proliferation. Forty-eight male Wistar rats had either 75 per cent proximal small bowel resection or jejunal transection. The animals were further divided into three groups, each with a different nutritional intake. The first group were allowed food ad libitum. The second group were kept under hypothermic conditions which resulted in hyperphagia, while the last group were nourished intravenously. A further 8 animals had a laparotomy only (sham operation). All animals were killed 12 days after operation, plasma Enteroglucagon and gastrin were measured, while determination of the crypt cell production rate (CCPR) was used to denote cellular proliferation. In each group resected rats had significantly higher crypt cell production rates and greater Enteroglucagon levels compared with transected animals. However, only in the normally fed group was plasma gastrin increased in resected animals, there being no significant difference in the plasma concentration of this peptide in transected compared with resected rats, in both the intravenously fed and hyperphagic groups. In the models studied Enteroglucagon appears to be a more likely candidate for a humoral trophic agent than gastrin in intestinal adaptation.

  • the influence of an intact pylorus on postprandial Enteroglucagon and neurotensin release after upper gastric surgery
    British Journal of Surgery, 2005
    Co-Authors: G R Sagor, M A Ghatei, G P Mcgregor, P Mitchenere, R M Kirk, S.r. Bloom
    Abstract:

    Upper partial gastrectomy for carcinoma of the gastric cardia or fundus is unavoidably accompanied by truncal vagotomy, so it is orthodox practice to carry out pyloroplasty with this procedure. In order to assess the effect of leaving an intact pylorus in this operation, 21 patients were investigated with an oral hypertonic load (200 ml 50 per cent glucose solution), and blood was taken at intervals during the test, for the ileal gut hormones, Enteroglucagon and neurotensin, as well as for measurements of haematocrit and blood glucose. Clinical features of dumping during the test were sought. There were 7 patients with upper partial gastrectomy, truncal vagotomy and an intact pylorus, 7 patients without a pylorus(total or near total gastrectomy) and 7 patients not subjected to gastric surgery. No significant difference was found in any of the measurements between gastrectomy patients with an intact pylorus andthose draining through an enterostomy. However, both these groups differed significantly from normal controls in havinggreater rates of rise and higher peak values of Enteroglucagon, neurotensin, haematocrit and blood glucose, together witha more frequent occurrence of dumping symptoms during the test. As the above measurements probably reflect transit of glucose into the small intestine, the findings in this study suggest that leaving an intact unstenosed pylorus is unlikely to lead to gastric stasis following upper partial gastrectomy.

  • fermentable dietary fibre intestinal microflora and plasma hormones in the rat
    Clinical Science, 1997
    Co-Authors: M A Ghatei, S.r. Bloom, B Ratcliffe, R A Goodlad
    Abstract:

    1. Conventional and germ-free rats were fed a fibre-free elemental diet with or without the addition of fermentable dietary fibres. We have previously reported that fibre was associated with greatly increased epithelial cell proliferation, but only in the conventional group, implying that it is the breakdown of fibre by the colonic microflora that is the main determinant of mucosal proliferation in the hind gut. The relationship of these changes to various plasma hormones implicated in intestinal growth control are described in this paper. 2. The most dramatic finding was that plasma levels of Enteroglucagon and peptide YY were greatly increased in the germ-free groups. The response of these rats to fibre differed in that fibre decreased levels of Enteroglucagon and peptide YY in the germ-free animals, but increased them in the conventional rats. Gastrin and insulin levels were significantly lowered in the fibre-supplemented groups, but were not affected by the microflora. 3. These results corroborate our previous findings that the effects of fibre and its fermentation are dynamically complex, and demonstrate that, like proliferation, direct effects and indirect fermentation-derived effects on plasma hormones also coexist.

  • release of vasodilator but not vasoconstrictor neuropeptides and of Enteroglucagon by intestinal ischaemia reperfusion in the rat
    Gut, 1994
    Co-Authors: L Meleagros, M A Ghatei, S.r. Bloom
    Abstract:

    Reperfusion of ischaemic intestine is characterised by an initial hyperaemia with ensuing mucosal repair. This study investigated possible roles for gut vasoactive neuropeptides and trophic peptides in these phenomena. Groups of rats were monitored during superior mesenteric artery occlusion for five or 20 minutes, with or without subsequent reperfusion for five minutes. Peptide concentrations (fmol/ml) in arterial blood, were measured using specific radioimmunoassays. Intestinal ischaemia alone did not cause haemodynamic disturbance or peptide release. Reperfusion, after five minutes of ischaemia, resulted in arterial hypotension and a rise in plasma vasoactive intestinal polypeptide (mean (SEM)) (37 (3), control 11 (4), p < 0.001). After 20 minutes of ischaemia, reperfusion resulted in greater hypotension (p < 0.05) and release of both vasoactive intestinal polypeptide (31 (3), p < 0.05 v control) and the more potent vasodilator beta-calcitonin gene related peptide (49 (3), control 23 (1), p < 0.001). By contrast, the vasodilators alpha-calcitonin gene related peptide and substance P and the vasoconstrictors neuropeptide Y, peptide YY, and somatostatin were not released. Bombesin, a stimulatory neuropeptide, was released after 20 minutes of ischaemia/reperfusion (13 (2), control 7 (3), p < 0.05). Plasma Enteroglucagon rose from control (51 (4)) to 110 (16) (p < 0.001) and to 158 (27) (p < 0.005) after five and 20 minutes of ischaemia/reperfusion. The potent enteric vasodilators vasoactive intestinal polypeptide and beta-calcitonin gene related peptide, unopposed by vasoconstrictors, may promote post-ischaemic intestinal hyperaemia. The rise in plasma Enteroglucagon may point to diffuse mucosal injury and is consistent with the putative trophic role of this peptide.

M A Ghatei - One of the best experts on this subject based on the ideXlab platform.

  • the role of pancreatico biliary secretions in intestinal adaptation after resection and its relationship to plasma Enteroglucagon
    British Journal of Surgery, 2005
    Co-Authors: M Y T Almukhtar, S.r. Bloom, M A Ghatei, G R Sagor, N A Wright
    Abstract:

    Two groups, each containing 16 male Wistar rats, had either 75 per cent small bowel resection or jejunal transection; 8 animals from each group; had previously been subjected to pancreatico-biliary diversion. All animals were killed 12 days after the operation, plasma Enteroglucagon levels were measured and crypt cell production rate (CCPR) at different sites of the remaining small intestine was measured using a metaphase arrest technique with vincristine. In each of the resected groups there was a significant increase in the CCPR and Enteroglucagon levels compared with the transected groups. Furthermore it was found that the CCPR and Enteroglucagon levels were higher in the resected group without the pancreatico-biliary diversion compared with the resected group with the diversion. This study, although it confirms the importance of pancreatico-biliary secretions in intestinal adaptation, could also indicate that a humoral factor may be important in the control of intestinal cell proliferation. Our findings do not exclude the possibility that Enteroglucagon could be a candidate for such a role.

  • the effect of altered luminal nutrition on cellular proliferation and plasma concentrations of Enteroglucagon and gastrin after small bowel resection in the rat
    British Journal of Surgery, 2005
    Co-Authors: G R Sagor, N A Wright, M A Ghatei, M Y T Almukhtar, S.r. Bloom
    Abstract:

    Luminal nutrition is known to have a trophic effect on small bowel mucosa after intestinal resection. Humoral agents, however, may also contribute to this process. Two of the proposed humoral agents, Enteroglucagon and gastrin, were therefore investigated after intestinal resection and transection in the rat, and changes in their concentration in the plasma were related to cellular proliferation. Forty-eight male Wistar rats had either 75 per cent proximal small bowel resection or jejunal transection. The animals were further divided into three groups, each with a different nutritional intake. The first group were allowed food ad libitum. The second group were kept under hypothermic conditions which resulted in hyperphagia, while the last group were nourished intravenously. A further 8 animals had a laparotomy only (sham operation). All animals were killed 12 days after operation, plasma Enteroglucagon and gastrin were measured, while determination of the crypt cell production rate (CCPR) was used to denote cellular proliferation. In each group resected rats had significantly higher crypt cell production rates and greater Enteroglucagon levels compared with transected animals. However, only in the normally fed group was plasma gastrin increased in resected animals, there being no significant difference in the plasma concentration of this peptide in transected compared with resected rats, in both the intravenously fed and hyperphagic groups. In the models studied Enteroglucagon appears to be a more likely candidate for a humoral trophic agent than gastrin in intestinal adaptation.

  • the influence of an intact pylorus on postprandial Enteroglucagon and neurotensin release after upper gastric surgery
    British Journal of Surgery, 2005
    Co-Authors: G R Sagor, M A Ghatei, G P Mcgregor, P Mitchenere, R M Kirk, S.r. Bloom
    Abstract:

    Upper partial gastrectomy for carcinoma of the gastric cardia or fundus is unavoidably accompanied by truncal vagotomy, so it is orthodox practice to carry out pyloroplasty with this procedure. In order to assess the effect of leaving an intact pylorus in this operation, 21 patients were investigated with an oral hypertonic load (200 ml 50 per cent glucose solution), and blood was taken at intervals during the test, for the ileal gut hormones, Enteroglucagon and neurotensin, as well as for measurements of haematocrit and blood glucose. Clinical features of dumping during the test were sought. There were 7 patients with upper partial gastrectomy, truncal vagotomy and an intact pylorus, 7 patients without a pylorus(total or near total gastrectomy) and 7 patients not subjected to gastric surgery. No significant difference was found in any of the measurements between gastrectomy patients with an intact pylorus andthose draining through an enterostomy. However, both these groups differed significantly from normal controls in havinggreater rates of rise and higher peak values of Enteroglucagon, neurotensin, haematocrit and blood glucose, together witha more frequent occurrence of dumping symptoms during the test. As the above measurements probably reflect transit of glucose into the small intestine, the findings in this study suggest that leaving an intact unstenosed pylorus is unlikely to lead to gastric stasis following upper partial gastrectomy.

  • fermentable dietary fibre intestinal microflora and plasma hormones in the rat
    Clinical Science, 1997
    Co-Authors: M A Ghatei, S.r. Bloom, B Ratcliffe, R A Goodlad
    Abstract:

    1. Conventional and germ-free rats were fed a fibre-free elemental diet with or without the addition of fermentable dietary fibres. We have previously reported that fibre was associated with greatly increased epithelial cell proliferation, but only in the conventional group, implying that it is the breakdown of fibre by the colonic microflora that is the main determinant of mucosal proliferation in the hind gut. The relationship of these changes to various plasma hormones implicated in intestinal growth control are described in this paper. 2. The most dramatic finding was that plasma levels of Enteroglucagon and peptide YY were greatly increased in the germ-free groups. The response of these rats to fibre differed in that fibre decreased levels of Enteroglucagon and peptide YY in the germ-free animals, but increased them in the conventional rats. Gastrin and insulin levels were significantly lowered in the fibre-supplemented groups, but were not affected by the microflora. 3. These results corroborate our previous findings that the effects of fibre and its fermentation are dynamically complex, and demonstrate that, like proliferation, direct effects and indirect fermentation-derived effects on plasma hormones also coexist.

  • release of vasodilator but not vasoconstrictor neuropeptides and of Enteroglucagon by intestinal ischaemia reperfusion in the rat
    Gut, 1994
    Co-Authors: L Meleagros, M A Ghatei, S.r. Bloom
    Abstract:

    Reperfusion of ischaemic intestine is characterised by an initial hyperaemia with ensuing mucosal repair. This study investigated possible roles for gut vasoactive neuropeptides and trophic peptides in these phenomena. Groups of rats were monitored during superior mesenteric artery occlusion for five or 20 minutes, with or without subsequent reperfusion for five minutes. Peptide concentrations (fmol/ml) in arterial blood, were measured using specific radioimmunoassays. Intestinal ischaemia alone did not cause haemodynamic disturbance or peptide release. Reperfusion, after five minutes of ischaemia, resulted in arterial hypotension and a rise in plasma vasoactive intestinal polypeptide (mean (SEM)) (37 (3), control 11 (4), p < 0.001). After 20 minutes of ischaemia, reperfusion resulted in greater hypotension (p < 0.05) and release of both vasoactive intestinal polypeptide (31 (3), p < 0.05 v control) and the more potent vasodilator beta-calcitonin gene related peptide (49 (3), control 23 (1), p < 0.001). By contrast, the vasodilators alpha-calcitonin gene related peptide and substance P and the vasoconstrictors neuropeptide Y, peptide YY, and somatostatin were not released. Bombesin, a stimulatory neuropeptide, was released after 20 minutes of ischaemia/reperfusion (13 (2), control 7 (3), p < 0.05). Plasma Enteroglucagon rose from control (51 (4)) to 110 (16) (p < 0.001) and to 158 (27) (p < 0.005) after five and 20 minutes of ischaemia/reperfusion. The potent enteric vasodilators vasoactive intestinal polypeptide and beta-calcitonin gene related peptide, unopposed by vasoconstrictors, may promote post-ischaemic intestinal hyperaemia. The rise in plasma Enteroglucagon may point to diffuse mucosal injury and is consistent with the putative trophic role of this peptide.

Irvin M Modlin - One of the best experts on this subject based on the ideXlab platform.

  • deoxycholate is an important releaser of peptide yy and Enteroglucagon from the human colon
    Gut, 1993
    Co-Authors: Thomas E Adrian, Anton J Bilchik, Garth H Ballantyne, Walter E Longo, S M Graham, Marc D Basson, R P Tierney, Irvin M Modlin
    Abstract:

    Peptide YY (PYY) and Enteroglucagon are hormonal peptides found in endocrine cells of the distal intestinal mucosa. Although it is known that plasma concentrations of both peptides increase in response to feeding, the mechanism by which ingested food causes release of colonic hormones is not understood. The release of PYY and Enteroglucagon was measured in response to intraluminal stimuli in 176 patients having investigative colonoscopy. Introduction of air, saline (isotonic and hypertonic), glucose (isotonic and hypertonic), oleic acid (without bile salts), and casein hydrolysate all failed to release PYY but glucose caused a small but significant increase in Enteroglucagon concentrations. In contrast with the lack of effect of nutrients, infusion of deoxycholic acid produced a rapid and marked dose responsive increase in plasma PYY concentrations when introduced into the sigmoid colon. PYY release was statistically significant at doses between 3.3 mM to 30 mM; for example 10 mM deoxycholate caused a sixfold increase in plasma PYY concentrations. Infusion of 10 mM deoxycholate into the transverse colon or caecum produced an increase of PYY that was similar to the responses in the sigmoid colon. There was also a significant release of Enteroglucagon in response to infusion of this bile salt into the sigmoid colon at doses between 3.3 mM and 30 mM. The Enteroglucagon response to 10 mM deoxycholate was similar in all three colonic regions. When oleic acid was added to deoxycholate as an emulsion, the release of PYY and Enteroglucagon was similar to that seen with the bile salt alone. These findings suggest that bile salts may play an important part in the control of colonic endocrine function and may explain the increased circulating concentrations of colonic regulatory peptides that are seen in malabsorption states and after small bowel resection in humans.

  • distribution and immunocytochemical colocalization of peptide yy and Enteroglucagon in endocrine cells of the rabbit colon
    Endocrinology, 1991
    Co-Authors: O Nilsson, Thomas E Adrian, Anton J Bilchik, James R Goldenring, Garth H Ballantyne, Irvin M Modlin
    Abstract:

    Peptide YY (PYY) is 36 amino acid peptide hormone present in high concentrations in the colon where it is colocalized with Enteroglucagon in L cells. A selective release of PYY and Enteroglucagon from the rabbit colon has been described, raising the question of the exact localization of the two hormones in the rabbit colon. We have therefore examined the distribution of PYY and Enteroglucagon as well as somatostatin in the rabbit colon using RIA and electron microscopic immunocytochemistry. PYY and Enteroglucagon were present in high concentrations in the colorectal mucosa with peak concentrations in the left colon (PYY 544 +/- 87 pmol/g, Enteroglucagon 152 +/- 10 pmol/g). Electron microscopic examination of the colonic mucosa demonstrated a large population (65%) of EC cells, a moderate population (30%) of L cells, and a small population (5%) of D cells. By immunogold labeling serotonin was localized to EC cells, PYY and Enteroglucagon to L cells, and somatostatin to the D cell. Double immunogold labeling revealed PYY and Enteroglucagon in all L cells examined (93 cells). A majority of the secretory granules (83%) were labeled by both PYY and glucagon antibodies, whereas a significant portion of granules (15%) was labeled by the PYY antibodies alone. The results demonstrate that L cells are the sole source of PYY and Enteroglucagon in the rabbit colon and that L cells contain different populations of secretory granules. The existence of different secretory granules in L cells may explain the selective release of PYY and Enteroglucagon observed in the rabbit colon.

  • Adaptive increase in peptide YY and Enteroglucagon after proctocolectomy and pelvic ileal reservoir construction
    Diseases of the Colon & Rectum, 1991
    Co-Authors: David N. Armstrong, Thomas E Adrian, Anton J Bilchik, Garth H Ballantyne, Marvin A. Mcmillen, Irvin M Modlin
    Abstract:

    Functional results improve with time after proctocolectomy and pelvic ileal reservoir construction. We hypothesized that adaptive increases of circulating and tissue levels of the gut hormones peptide YY (PYY) and Enteroglucagon may contribute to this improvement by slowing small bowel transit and increasing small bowel absorption. The specific aim of this study was to measure plasma and ileal mucosal concentrations of PYY and Enteroglucagon in dogs 1 year after proctocolectomy and ileal reservoir-anal anastomosis. In the ileal reservoir dogs, postprandial PYY levels reached 238±31 pmol/ liter compared with 93±33 pmol/liter in sham operated controls ( P < 0.001). Postprandial plasma Enteroglucagon levels reached 199±53 pmol/liter in reservoir animals and 52±4 pmol/liter in controls ( P < 0.05). Tissue levels of PYY in the mucosa of the ileal reservoirs were 419±43 pmol/g compared with 133±23 pmol/ g in normal terminal ileum ( P < 0.0001). Enteroglucagon levels were also elevated in reservoir mucosa (193 ±21 pmol/g vs . 113±9 pmol/g in controls , P < 0.05). These data demonstrate that postprandial and tissue levels of PYY and Enteroglucagon increase in dogs 1 year after construction of ileal reservoirs. The adaptive increase in PYY would slow small bowel transit and the increase in Enteroglucagon would promote mucosal growth, each contributing to the improved functional results .

Thomas E Adrian - One of the best experts on this subject based on the ideXlab platform.

  • role of peptide yy and Enteroglucagon after low anterior resection comparison between straight and colonic j pouch anastomosis
    Diseases of The Colon & Rectum, 1996
    Co-Authors: Olof Hallbook, Thomas E Adrian, Johan Permert, Paul Staab
    Abstract:

    PURPOSE: It has been shown in several studies that a colonic J-pouch obviates much of the early dysfunction after a low anterior resection in terms of urgent and frequent bowel movements. In search for specific mediators of the postoperative functional adaptation, two gut peptides, peptide YY and Enteroglucagon, were studied. METHODS: Plasma and “neorectal” mucosal levels of both peptides were measured in 12 patients with a straight coloanal anastomosis and in 11 patients with a colonic J-pouch anastomosis. Patients were part of a randomized trial comparing straight and colonic pouch anastomosis. Fasting plasma samples of both peptides were collected intraoperatively, after one week, before loop ileostomy closure, and at 1, 3, and 12 months after loop ileostomy closure. RESULTS: There was no difference between the straight and the pouch groups in plasma concentrations of either peptide at any time period postoperatively. The only longitudinal hormonal changes were transient increases in mucosal peptide YY content at one-month follow-up and in mucosal Enteroglucagon content before loop ileostomy closure. CONCLUSION: Peptide YY and Enteroglucagon responses in these patients appear not to be major factors for improved out-come after formation of a colonic pouch in low anterior resection.

  • early regional expression and secretion of peptide yy and Enteroglucagon after massive resection of small bowel
    Journal of The American College of Surgeons, 1995
    Co-Authors: Anton J Bilchik, Thomas E Adrian, Oscar J Hines, Michael J Skotzko, David W Mcfadden, Michael J Zinner, Stanley W Ashley
    Abstract:

    BACKGROUND Previous studies suggest that peptide YY (PYY) and Enteroglucagon have an important role in intestinal adaptation after massive small bowel resection. This study was done to define the mechanisms, timing, and anatomic distribution of the PYY and Enteroglucagon response. STUDY DESIGN Lewis rats underwent resection of 70 percent of the small bowel (leaving equal segments of jejunum and ileum), transection, or laparotomy alone. Jejunum, ileum, and colon were compared in resected, transected, and control bowel six hours, 24 hours, one week, and two weeks postoperatively. RESULTS Analysis of DNA, RNA, and protein per cm of bowel demonstrated hyperplastic changes. Radioimmunoassay revealed plasma PYY and Enteroglucagon to be significantly elevated 24 hours after resection and they remained so through week two. In contrast, tissue PYY and Enteroglucagon content decreased significantly in all tissues (p < 0.05) after resection. Reverse transcriptase polymerase chain reaction and Southern blot analysis demonstrated an immediate and sustained increase in PYY messenger RNA (mRNA) in both the ileum (fourfold) and in the colon (2.5-fold) at six hours (p < 0.05). A gradual increase in PYY mRNA was also demonstrated in the jejunum with significance at two weeks (p < 0.05). Proglucagon mRNA was significantly higher in the jejunum, compared with the ileum and colon, at 24 hours, one week, and two weeks postresection. CONCLUSIONS Alterations in PYY and Enteroglucagon synthesis occur early in the ileum and colon after massive small bowel resection. The residual jejunum, however, is primarily responsible for the adaptive hyperEnteroglucagonemia. These findings suggest that although PYY and Enteroglucagon are colocalized to the same cell type, there is a gene-specific response for these two peptides after resection.

  • deoxycholate is an important releaser of peptide yy and Enteroglucagon from the human colon
    Gut, 1993
    Co-Authors: Thomas E Adrian, Anton J Bilchik, Garth H Ballantyne, Walter E Longo, S M Graham, Marc D Basson, R P Tierney, Irvin M Modlin
    Abstract:

    Peptide YY (PYY) and Enteroglucagon are hormonal peptides found in endocrine cells of the distal intestinal mucosa. Although it is known that plasma concentrations of both peptides increase in response to feeding, the mechanism by which ingested food causes release of colonic hormones is not understood. The release of PYY and Enteroglucagon was measured in response to intraluminal stimuli in 176 patients having investigative colonoscopy. Introduction of air, saline (isotonic and hypertonic), glucose (isotonic and hypertonic), oleic acid (without bile salts), and casein hydrolysate all failed to release PYY but glucose caused a small but significant increase in Enteroglucagon concentrations. In contrast with the lack of effect of nutrients, infusion of deoxycholic acid produced a rapid and marked dose responsive increase in plasma PYY concentrations when introduced into the sigmoid colon. PYY release was statistically significant at doses between 3.3 mM to 30 mM; for example 10 mM deoxycholate caused a sixfold increase in plasma PYY concentrations. Infusion of 10 mM deoxycholate into the transverse colon or caecum produced an increase of PYY that was similar to the responses in the sigmoid colon. There was also a significant release of Enteroglucagon in response to infusion of this bile salt into the sigmoid colon at doses between 3.3 mM and 30 mM. The Enteroglucagon response to 10 mM deoxycholate was similar in all three colonic regions. When oleic acid was added to deoxycholate as an emulsion, the release of PYY and Enteroglucagon was similar to that seen with the bile salt alone. These findings suggest that bile salts may play an important part in the control of colonic endocrine function and may explain the increased circulating concentrations of colonic regulatory peptides that are seen in malabsorption states and after small bowel resection in humans.

  • abnormal plasma gut hormones in pathologic duodenogastric reflux and their response to surgery
    American Journal of Surgery, 1992
    Co-Authors: Paul Wilson, Neil T Welch, Ronald A Hinder, Marco Anselmino, Margery K Herrington, Tom R Demeester, Thomas E Adrian
    Abstract:

    Fasting and postprandial plasma levels of the gut hormones gastrin, cholecystokinin (CCK), secretin, glucose-dependent insulinotropic polypeptide, motilin, neurotensin, peptide YY (PYY), Enteroglucagon, glucagon, insulin, and pancreatic polypeptide were measured in 11 patients with alkaline gastritis associated with excessive duodenogastric reflux not related to previous gastric surgery (primary DGR), 12 primary DGR patients after pancreatico-biliary diversion ("duodenal switch" procedure), and in 10 age-matched healthy controls. Gastric emptying of a semisolid oatmeal was also measured in patients with primary DGR and in patients after bile diversion. Fasting plasma levels of the distal gut hormone neurotensin and the pancreatic islet hormone insulin were significantly greater in patients with primary DGR compared with controls. Neurotensin levels were normal in patients studied after bile diversion. Postprandial plasma levels, incremental integrated and total integrated responses for CCK, secretin, insulin, neurotensin, PYY, and Enteroglucagon, were significantly greater in patients with primary DGR compared with controls. The majority of these responses normalized after bile diversion; however, the postprandial response for insulin and Enteroglucagon remained elevated. Patients with primary DGR had a rapid early post-prandial phase of gastric emptying of solids, which showed a significant correlation with plasma neurotensin levels. Bile diversion produced a significant delay in this lag-phase of gastric emptying. These abnormalities in gut regulatory hormones appear to be adaptive changes to rapid early postprandial gastric emptying, probably related to antropyloric dysmotility, which has been implicated in the pathogenesis of this condition. Measurement of these gastrointestinal hormones may become useful in the diagnosis of primary DGR.

  • plasma and tissue alterations of peptide yy and Enteroglucagon in rats after colectomy
    Yale Journal of Biology and Medicine, 1992
    Co-Authors: A P Vukasin, Thomas E Adrian, O Nilsson, Anton J Bilchik, Garth H Ballantyne, I M Modlin
    Abstract:

    Peptide YY (PYY) and Enteroglucagon are produced by endocrine cells of the colonic mucosa. PYY inhibits upper gastrointestinal motility, and Enteroglucagon is trophic for small bowel mucosa. Adaptive increase in the production and release of these peptides may improve functional results after colorectal resections. We hypothesized that if segments of the colon were resected, then production and release of PYY and Enteroglucagon would increase in the remaining segments of bowel. Animals which underwent colonic transections and partial resections had transient elevations of PYY up to 250 +/- 80 pmol/L, which dropped to control group levels in the second week following surgery. Rats with an abdominal colectomy had significantly greater PYY levels than all other groups from the third (208 +/- 30 pmol/L) to the thirty-eighth (100 +/- 16 pmol/L) week of the study. Circulating levels of Enteroglucagon were elevated to 156 +/- 35 pmol/L in rats with a right hemicolectomy during the first week following surgery. Enteroglucagon levels did not significantly vary in the other groups studied. Both tissue PYY (413 +/- 33 pmol/gram) and tissue Enteroglucagon (171 +/- 17 pmol/gram) were significantly elevated in the rectums of the rats with an abdominal colectomy, as compared to all other groups. The elevated tissue levels may thus account for the ability to maintain elevated plasma PYY. Double immunogold labeling of endocrine cells in the colorectal tissue for PYY and Enteroglucagon revealed both peptides within the same endocrine cells and secretory granules. These studies support the hypothesis that circulating levels of PYY are elevated after major colonic resections and suggest that L-type endocrine cells may participate in adaptive responses which improve intestinal function following colonic surgery.

Anton J Bilchik - One of the best experts on this subject based on the ideXlab platform.

  • early regional expression and secretion of peptide yy and Enteroglucagon after massive resection of small bowel
    Journal of The American College of Surgeons, 1995
    Co-Authors: Anton J Bilchik, Thomas E Adrian, Oscar J Hines, Michael J Skotzko, David W Mcfadden, Michael J Zinner, Stanley W Ashley
    Abstract:

    BACKGROUND Previous studies suggest that peptide YY (PYY) and Enteroglucagon have an important role in intestinal adaptation after massive small bowel resection. This study was done to define the mechanisms, timing, and anatomic distribution of the PYY and Enteroglucagon response. STUDY DESIGN Lewis rats underwent resection of 70 percent of the small bowel (leaving equal segments of jejunum and ileum), transection, or laparotomy alone. Jejunum, ileum, and colon were compared in resected, transected, and control bowel six hours, 24 hours, one week, and two weeks postoperatively. RESULTS Analysis of DNA, RNA, and protein per cm of bowel demonstrated hyperplastic changes. Radioimmunoassay revealed plasma PYY and Enteroglucagon to be significantly elevated 24 hours after resection and they remained so through week two. In contrast, tissue PYY and Enteroglucagon content decreased significantly in all tissues (p < 0.05) after resection. Reverse transcriptase polymerase chain reaction and Southern blot analysis demonstrated an immediate and sustained increase in PYY messenger RNA (mRNA) in both the ileum (fourfold) and in the colon (2.5-fold) at six hours (p < 0.05). A gradual increase in PYY mRNA was also demonstrated in the jejunum with significance at two weeks (p < 0.05). Proglucagon mRNA was significantly higher in the jejunum, compared with the ileum and colon, at 24 hours, one week, and two weeks postresection. CONCLUSIONS Alterations in PYY and Enteroglucagon synthesis occur early in the ileum and colon after massive small bowel resection. The residual jejunum, however, is primarily responsible for the adaptive hyperEnteroglucagonemia. These findings suggest that although PYY and Enteroglucagon are colocalized to the same cell type, there is a gene-specific response for these two peptides after resection.

  • deoxycholate is an important releaser of peptide yy and Enteroglucagon from the human colon
    Gut, 1993
    Co-Authors: Thomas E Adrian, Anton J Bilchik, Garth H Ballantyne, Walter E Longo, S M Graham, Marc D Basson, R P Tierney, Irvin M Modlin
    Abstract:

    Peptide YY (PYY) and Enteroglucagon are hormonal peptides found in endocrine cells of the distal intestinal mucosa. Although it is known that plasma concentrations of both peptides increase in response to feeding, the mechanism by which ingested food causes release of colonic hormones is not understood. The release of PYY and Enteroglucagon was measured in response to intraluminal stimuli in 176 patients having investigative colonoscopy. Introduction of air, saline (isotonic and hypertonic), glucose (isotonic and hypertonic), oleic acid (without bile salts), and casein hydrolysate all failed to release PYY but glucose caused a small but significant increase in Enteroglucagon concentrations. In contrast with the lack of effect of nutrients, infusion of deoxycholic acid produced a rapid and marked dose responsive increase in plasma PYY concentrations when introduced into the sigmoid colon. PYY release was statistically significant at doses between 3.3 mM to 30 mM; for example 10 mM deoxycholate caused a sixfold increase in plasma PYY concentrations. Infusion of 10 mM deoxycholate into the transverse colon or caecum produced an increase of PYY that was similar to the responses in the sigmoid colon. There was also a significant release of Enteroglucagon in response to infusion of this bile salt into the sigmoid colon at doses between 3.3 mM and 30 mM. The Enteroglucagon response to 10 mM deoxycholate was similar in all three colonic regions. When oleic acid was added to deoxycholate as an emulsion, the release of PYY and Enteroglucagon was similar to that seen with the bile salt alone. These findings suggest that bile salts may play an important part in the control of colonic endocrine function and may explain the increased circulating concentrations of colonic regulatory peptides that are seen in malabsorption states and after small bowel resection in humans.

  • plasma and tissue alterations of peptide yy and Enteroglucagon in rats after colectomy
    Yale Journal of Biology and Medicine, 1992
    Co-Authors: A P Vukasin, Thomas E Adrian, O Nilsson, Anton J Bilchik, Garth H Ballantyne, I M Modlin
    Abstract:

    Peptide YY (PYY) and Enteroglucagon are produced by endocrine cells of the colonic mucosa. PYY inhibits upper gastrointestinal motility, and Enteroglucagon is trophic for small bowel mucosa. Adaptive increase in the production and release of these peptides may improve functional results after colorectal resections. We hypothesized that if segments of the colon were resected, then production and release of PYY and Enteroglucagon would increase in the remaining segments of bowel. Animals which underwent colonic transections and partial resections had transient elevations of PYY up to 250 +/- 80 pmol/L, which dropped to control group levels in the second week following surgery. Rats with an abdominal colectomy had significantly greater PYY levels than all other groups from the third (208 +/- 30 pmol/L) to the thirty-eighth (100 +/- 16 pmol/L) week of the study. Circulating levels of Enteroglucagon were elevated to 156 +/- 35 pmol/L in rats with a right hemicolectomy during the first week following surgery. Enteroglucagon levels did not significantly vary in the other groups studied. Both tissue PYY (413 +/- 33 pmol/gram) and tissue Enteroglucagon (171 +/- 17 pmol/gram) were significantly elevated in the rectums of the rats with an abdominal colectomy, as compared to all other groups. The elevated tissue levels may thus account for the ability to maintain elevated plasma PYY. Double immunogold labeling of endocrine cells in the colorectal tissue for PYY and Enteroglucagon revealed both peptides within the same endocrine cells and secretory granules. These studies support the hypothesis that circulating levels of PYY are elevated after major colonic resections and suggest that L-type endocrine cells may participate in adaptive responses which improve intestinal function following colonic surgery.

  • distribution and immunocytochemical colocalization of peptide yy and Enteroglucagon in endocrine cells of the rabbit colon
    Endocrinology, 1991
    Co-Authors: O Nilsson, Thomas E Adrian, Anton J Bilchik, James R Goldenring, Garth H Ballantyne, Irvin M Modlin
    Abstract:

    Peptide YY (PYY) is 36 amino acid peptide hormone present in high concentrations in the colon where it is colocalized with Enteroglucagon in L cells. A selective release of PYY and Enteroglucagon from the rabbit colon has been described, raising the question of the exact localization of the two hormones in the rabbit colon. We have therefore examined the distribution of PYY and Enteroglucagon as well as somatostatin in the rabbit colon using RIA and electron microscopic immunocytochemistry. PYY and Enteroglucagon were present in high concentrations in the colorectal mucosa with peak concentrations in the left colon (PYY 544 +/- 87 pmol/g, Enteroglucagon 152 +/- 10 pmol/g). Electron microscopic examination of the colonic mucosa demonstrated a large population (65%) of EC cells, a moderate population (30%) of L cells, and a small population (5%) of D cells. By immunogold labeling serotonin was localized to EC cells, PYY and Enteroglucagon to L cells, and somatostatin to the D cell. Double immunogold labeling revealed PYY and Enteroglucagon in all L cells examined (93 cells). A majority of the secretory granules (83%) were labeled by both PYY and glucagon antibodies, whereas a significant portion of granules (15%) was labeled by the PYY antibodies alone. The results demonstrate that L cells are the sole source of PYY and Enteroglucagon in the rabbit colon and that L cells contain different populations of secretory granules. The existence of different secretory granules in L cells may explain the selective release of PYY and Enteroglucagon observed in the rabbit colon.

  • Adaptive increase in peptide YY and Enteroglucagon after proctocolectomy and pelvic ileal reservoir construction
    Diseases of the Colon & Rectum, 1991
    Co-Authors: David N. Armstrong, Thomas E Adrian, Anton J Bilchik, Garth H Ballantyne, Marvin A. Mcmillen, Irvin M Modlin
    Abstract:

    Functional results improve with time after proctocolectomy and pelvic ileal reservoir construction. We hypothesized that adaptive increases of circulating and tissue levels of the gut hormones peptide YY (PYY) and Enteroglucagon may contribute to this improvement by slowing small bowel transit and increasing small bowel absorption. The specific aim of this study was to measure plasma and ileal mucosal concentrations of PYY and Enteroglucagon in dogs 1 year after proctocolectomy and ileal reservoir-anal anastomosis. In the ileal reservoir dogs, postprandial PYY levels reached 238±31 pmol/ liter compared with 93±33 pmol/liter in sham operated controls ( P < 0.001). Postprandial plasma Enteroglucagon levels reached 199±53 pmol/liter in reservoir animals and 52±4 pmol/liter in controls ( P < 0.05). Tissue levels of PYY in the mucosa of the ileal reservoirs were 419±43 pmol/g compared with 133±23 pmol/ g in normal terminal ileum ( P < 0.0001). Enteroglucagon levels were also elevated in reservoir mucosa (193 ±21 pmol/g vs . 113±9 pmol/g in controls , P < 0.05). These data demonstrate that postprandial and tissue levels of PYY and Enteroglucagon increase in dogs 1 year after construction of ileal reservoirs. The adaptive increase in PYY would slow small bowel transit and the increase in Enteroglucagon would promote mucosal growth, each contributing to the improved functional results .