The Experts below are selected from a list of 78516 Experts worldwide ranked by ideXlab platform
Juan-r. Malagelada - One of the best experts on this subject based on the ideXlab platform.
-
Gastric wall tension determines perception of gastric Distention
Gastroenterology, 1999Co-Authors: Eleonora Distrutti, Fernando Azpiroz, Alfredo Soldevilla, Juan-r. MalageladaAbstract:Abstract Background & Aims: The primary mechanism that originates symptoms in response to gastric Distention remains undefined. The aim of this study was to determine which factor, whether intragastric volume, pressure, or wall tension, determines perception of gastric Distention. Methods: Healthy subjects underwent increasing gastric Distentions (2-minute duration at 5-minute intervals) either at fixed pressure levels using a conventional barostat (n = 10) or at fixed tension levels using a newly developed computerized tensostat (n = 12); perception was scored by a 0–6 scale. Distentions were performed during basal conditions (intravenous saline) and during gastric relaxation by glucagon administration (4.8 μg/kg intravenous bolus plus 9.6 μg · kg −1 · h −1 infusion). Results: Isobaric Distentions with the conventional barostat produced more intense perception during glucagon (95% ± 40% higher; P P P Conclusions: Gastric wall tension, but not intragastric volume, determines perception of gastric Distention, at least below nociception. GASTROENTEROLOGY 1999;116:1035-1042
-
the sympathetic nervous system modulates perception and reflex responses to gut Distention in humans
Gastroenterology, 1995Co-Authors: Paola Iovino, Fernando Azpiroz, Enrique Domingo, Juan-r. MalageladaAbstract:Abstract Background/Aims: Intestinal Distention induces perception and gut reflexes via sympathetic and vagal pathways, but the modulatory mechanisms of such responses remain obscure. The aim of this study was to determine the effects of sympathetic nervous activity on sympathetic and vagal reflexes as well as on intestinal and somatic perception. Methods: In 9 healthy volunteers, proximal duodenal Distentions were produced in 4-mL increments and hand transcutaneous electrical nerve stimulation was produced in 3-mA increments. Increasing stimuli of 1-minute duration were randomly performed at 10-minute intervals both with and without sympathetic activation (induced by means of lower body negative pressure). Intestinal and somatic perception was scored by specific questionnaires; vagal enterogastric and sympathetic intestinointestinal relaxatory reflexes were simultaneously measured by gastric and distal duodenal barostats. Results: Sympathetic activation significantly heightened perception of intestinal Distention without modifying perception of somatic stimuli (perception scores increased by 41% and −2%, respectively). The reflex responses to duodenal Distention significantly increased during sympathetic activation both in the stomach and in the intestine (relaxation increased by 91% and 69%, respectively; P
-
gastric tone determines the sensitivity of the stomach to Distention
Gastroenterology, 1995Co-Authors: Ricardo Notivol, Fernando Azpiroz, Jordi Serra, Benoit Coffin, Fermin Mearin, Juan-r. MalageladaAbstract:Abstract Background/Aims: Whether meal-related symptoms such as postcibal epigastric fullness and discomfort are caused by hypotonic gastric expansion or gastric hypertension is unknown. This study investigated whether symptoms in healthy individuals in response to gastric Distention are produced by gastric expansion or by an increase in intragastric pressure. Methods: Increasing gastric Distentions (for 5 minutes at 5-minute intervals) at fixed pressure levels (in 2-mm Hg increments) and at fixed volume levels (in 200-mL increments) were performed in 10 healthy subjects per group; perception was measured on a 0–6 scale. Distentions were performed during intravenous infusion of saline (basal) and during gastric relaxation by intravenous administration of glucagon (4.8-μg/kg bolus plus 9.6 μg · kg −1 · h −1 infusion). Results: The same distending pressures tested produced 30% ± 9% larger intragastric volumes and 80% ± 44% higher perception scores when the stomach was relaxed by glucagon ( P P
-
Perception and reflex responses to intestinal Distention in humans are modified by simultaneous or previous stimulation
Gastroenterology, 1995Co-Authors: Jordi Serra, Fernando Azpiroz, Juan-r. MalageladaAbstract:Abstract Background & Aims: Intestinal reflexes induced by Distention in dogs are facilitated by either simultaneous or previous Distentions. The aim of this study was to determine whether these phenomena also modulate the responses to intestinal Distention, particularly perception, in humans. Methods: Perception and intestinal relaxation were measured in 11 healthy subjects in response to increasing jejunal balloon Distentions tested (by stimulus-response trials) alone, as control, and with conditioning Distentions applied either simultaneously, immediately (10 seconds) before at the same site, or immediately before and 5 cm distant. In 8 additional subjects, the effect of prolonged (90-minute) conditioning Distention was tested. Results: Conditioning had more pronounced effects on perception than on intestinal reflexes. Perception of intestinal Distention increased (by 84 ± 47%; P P
-
Sensorial and intestinointestinal reflex pathways in the human jejunum
Gastroenterology, 1991Co-Authors: Jean-michel Rouillon, Fernando Azpiroz, Juan-r. MalageladaAbstract:Abstract Using an intestinal barostat that maintains a constant pressure within an air-filled bag (12 cm long), the authors have previously shown reflex changes in intestinal tone induced by Distention. The aim of this study was to investigate the sensitivity and the responsiveness to such reflexes along the jejunum. Eight healthy volunteers were studied using two barostats operating simultaneously in the proximal and the distal jejunum (located 10 cm and 52 cm caudad to the ligament of Treitz, respectively). With one barostat, standardized Distentions (1 minute duration at 10-minute intervals in 4-mm Hg increments) were produced; with the other barostat, intestinal tone was measured as volumetric variations at constant pressure. Perception was scored (0–6) by a questionnaire. The proximal jejunum relaxed in response to Distention of the distal jejunum (mean ± SE, 40% + 7% Δvol; 5.1 + 0.1 perception score at the threshold for discomfort; P
Jan Tack - One of the best experts on this subject based on the ideXlab platform.
-
Startle responding in the context of visceral pain.
International journal of psychophysiology : official journal of the International Organization of Psychophysiology, 2015Co-Authors: Erik Ceunen, Jonas Zaman, Natacha Herssens, Lukas Van Oudenhove, Kathleen Bogaerts, Steven J. Coen, Jan Tack, Johan W.s. Vlaeyen, Ilse Van DiestAbstract:Abstract This study aimed to investigate affective modulation of eye blink startle by aversive visceral stimulation. Startle blink EMG responses were measured in 31 healthy participants receiving painful, intermittent balloon Distentions in the distal esophagus during 4 blocks (positive, negative, neutral or no pictures), and compared with startles during 3 ‘safe’ blocks without esophageal stimulations (positive, negative or neutral emotional pictures). Women showed enhanced startle during blocks with Distentions (as compared with ‘safe’ blocks), both when the balloon was in inflated and deflated states, suggesting that fear and/or expectations may have played a role. Men's startle did not differ between Distention and non-Distention blocks. In this particular study context affective picture viewing did not further impose any effect on startle eye blink responses. The current results may contribute to a better understanding of emotional reactions to aversive interoceptive stimulation.
-
Influence of a neurokinin-1 receptor antagonist (aprepitant) on gastric sensorimotor function in healthy volunteers.
Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society, 2013Co-Authors: Daphne Ang, Robin Vos, Ans Pauwels, F Akyuz, Jan TackAbstract:Background Substance P (SP) is a member of the neurokinin (NK) family and is one of the established neurotransmitters in the mammalian central and enteric nervous system. It is unclear whether NK1 receptors are involved in the control of gastric sensorimotor function in man. Methods We studied the effects of aprepitant, an NK1 receptor antagonist used in the treatment of chemotherapy-induced emesis, on gastric sensorimotor function in healthy volunteers. Sixteen healthy volunteers (six males, 32.4 ± 2.7 years) were studied on three separate occasions after placebo, aprepitant 80 or 125 mg in randomized double-blind study to assess gastric compliance, perception to isobaric distensions, and gastric accommodation with a gastric barostat. Key Results Compared to placebo, both doses of aprepitant did not influence gastric compliance or sensitivity to gastric distension. Aprepitant 80 and 125 mg did not have any significant effects on gastric accommodation compared with placebo (mean postprandial gastric volume increase, respectively, 83.4 ± 28.4 vs 35.3 ± 16.2 vs 83.9 ± 30.4 mL, NS). Postprandial gastric compliance and sensitivity to Distention were also not altered. Conclusions & Inferences In health, NK1 receptors do not appear to be involved in the control of gastric compliance, accommodation or sensitivity to Distention in man.
-
In Functional Dyspepsia, Hypersensitivity to Postprandial Distention Correlates With Meal-Related Symptom Severity
Gastroenterology, 2013Co-Authors: Ricard Farré, Lukas Van Oudenhove, Hanne Vanheel, Tim Vanuytsel, Tatsuhiro Masaoka, Hans Törnblom, Magnus Simrén, Jan TackAbstract:Background & Aims Hypersensitivity to gastric Distention, an important feature of functional dyspepsia, is assessed by stepwise balloon Distention of the proximal stomach in fasting patients. However, symptoms of functional dyspepsia are often worse after a meal, so studies of postprandial balloon Distentions might be more relevant. We compared the effects of fasting and postprandial stomach Distention in patients with functional dyspepsia. Methods Twenty healthy controls and 62 patients with functional dyspepsia participated in a gastric barostat study at Leuven University Hospital with graded isobaric Distentions before and after a liquid meal. On a separate day, all patients underwent a gastric emptying breath test with assessment of postprandial severity of 6 different dyspeptic symptoms scored at 15-minute intervals for 4 hours. For each symptom, a meal-related severity score was obtained by adding all scores; the cumulative symptom score (CSS) was obtained by adding individual symptom severity scores. Results In patients, but not in controls, postprandial sensitivity to balloon Distention was significantly greater than fasting sensitivity. The CSS and individual symptom scores did not differ between patients with normal or hypersensitivity to fasting Distention, but patients who were hypersensitive to postprandial Distention had a significantly higher CSS, along with scores for postprandial fullness, bloating, and nausea (all P Conclusions Postprandial, but not fasting, Distention thresholds are related to the severity of meal-related symptoms in patients with functional dyspepsia.
-
Influence of naloxone on rectal sensorimotor function in health.
Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society, 2009Co-Authors: Brecht Geeraerts, Robin Vos, Lukas Van Oudenhove, G. Karamanolis, Jan TackAbstract:Abnormal rectal motor physiology and visceral hypersensitivity are implicated in the pathogenesis of irritable bowel syndrome. Endogenous opioids are involved in both the regulation of gut motility and the processing of sensory information. Our aim was to study the effect of suppression of endogenous opioid function by naloxone on rectal sensorimotor function in health. Eighteen healthy subjects participated in a rectal barostat study. Sensorimotor function was evaluated during two consecutive stepwise distensions separated by 30 min of basal tone recording, and with perception scoring on a 0-6 graded scale. Naloxone was administered, after 15 min of basal tone measurements, as an intravenous bolus (0.4 mg), followed by continuous infusion (20 microg kg(-1) h(-1)) in a placebo-controlled, single-blinded and randomized fashion. Naloxone did not alter rectal sensitivity. Comparison of visual analogue scale scores between naloxone and saline did not reveal altered intensities of pain or discomfort. Compared to the baseline distension, a significant adaptive increase in compliance occurred during the second distension after saline (7.8 +/- 0.7 vs 11.0 +/- 0.6 mL mmHg(-1), P = 0.0016). This dynamic change in rectal compliance did not occur after naloxone administration (8.8 +/- 0.7 vs 10.1 +/- 0.8 mL mmHg(-1), ns). Low intensity tonic distension induced a rectal adaptive relaxation, which was absent after naloxone. Naloxone does not alter rectal sensitivity but abolishes rectal adaptation in response to repeated balloon Distention. These observations suggest that the endogenous opioid system is involved in control of rectal tone rather than rectal sensitivity.
-
The influence of the novel 5‐HT1A agonist R137696 on the proximal stomach function in healthy volunteers
Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society, 2006Co-Authors: Guy E. Boeckxstaens, G. N. J. Tytgat, E Wajs, L Van Nueten, F De Ridder, Ann Meulemans, Jan TackAbstract:Abstract As fundic dysaccommodation represents one of the pathophysiological mechanisms underlying functional dyspepsia, gastric relaxant agents may serve as a new treatment of this disorder. Previous studies have suggested the involvement of 5HT1 receptors in the control of gastric tone. Our aim was to study the effect of R137696, a novel 5HT1A agonist, on fundus sensorimotor function in healthy volunteers. The effect of single oral doses (1–2 mg) R137696 was evaluated in a double-blind, placebo-controlled manner on fasting fundic volume, visceral perception, distension-evoked symptoms and fundic compliance in 21 healthy male subjects. R137696 increased the proximal stomach volumes in a dose-dependent manner. Distention-evoked symptoms or Distention and discomfort threshold were not altered by R137696. A logistic regression model, characterizing the relationships between the volume and the visual analogue scale score for dyspeptic symptoms (nausea, fullness, discomfort, pain and satiety) as a sigmoidal curve, revealed that R137696 had no effect on distension-induced discomfort, fullness, pain and satiety compared to placebo. R137696 relaxes the gastric fundus in fasting conditions but has no effect on distension-evoked dyspeptic symptoms in healthy volunteers.
Richard J Traub - One of the best experts on this subject based on the ideXlab platform.
-
the visceromotor response to colorectal Distention fluctuates with the estrous cycle in rats
Neuroscience, 2008Co-Authors: Bin Tang, Richard J TraubAbstract:The existence of a sex difference in several chronic pain syndromes and the fluctuation of symptoms during the menstrual cycle strongly suggest sex hormones are involved in pain processing. The mechanisms underlying these changes are not well understood. Using the colorectal Distention model in the rat, we previously reported a sex difference in the response to Distention [Ji Y, Murphy AZ, Traub RJ (2006) Sex differences in morphine induced analgesia of visceral pain are supraspinally and peripherally mediated. Am J Physiol Regul Integr Comp Physiol 291:R307-R314] and that ovariectomy decreased the responses to Distention while estrogen replacement reversed the decrease [Ji Y, Murphy AZ, Traub RJ (2003) Estrogen modulates the visceromotor reflex and responses of spinal dorsal horn neurons to colorectal stimulation in the rat. J Neurosci 23:3908-3915], suggesting estrogen increases visceral nociception. In the present study we tested the hypothesis that the visceromotor response to colorectal Distention fluctuates with the estrous cycle. Three measurements (vaginal smears, uterine tube weight and plasma estrogen concentration) were used to determine the estrous phase. Comparison of the visceromotor response threshold and magnitude was made between proestrus and metestrus/diestrus. Our experiment demonstrated that the Distention threshold was significantly lower in proestrus (median: 15 mm Hg) as compared with metestrus/diestrus (median: 25 mm Hg); and the magnitude of the visceromotor response to graded intensities of colorectal Distentions (20, 40, 60, 80 mm Hg) was significantly higher in proestrus. The results indicate that the visceromotor response fluctuates with estrous phase, providing evidence for endogenous estrogen modulation of visceral nociceptive processing that could contribute to sex differences.
-
differential c fos expression in the nucleus of the solitary tract and spinal cord following noxious gastric Distention in the rat
Neuroscience, 1996Co-Authors: Richard J Traub, Jyoti N Sengupta, Gerald F. GebhartAbstract:Abstract c-Fos has been used as a marker for activity in the spinal cord following noxious somatic or visceral stimulation. Although the viscera receive dual afferent innervation, Distention of hollow organs (i.e. esophagus, stomach, descending colon and rectum) induces significantly more c-Fos in second order neurons in the nucleus of the solitary tract and lumbosacral spinal cord, which receive parasympathetic afferent input (vagus, pelvic nerves), than the thoracolumbar spinal cord, which receives sympathetic afferent input (splanchnic nerves). The purpose of this study was to determine the contribution of sympathetic and parasympathetic afferent input to c-Fos expression in the nucleus of the solitary tract and spinal cord, and the influence of supraspinal pathways on Fos induction in the thoracolumbar spinal cord. Noxious gastric Distention to 80 mmHg (gastric distension/80) was produced by repetitive inflation of a chronically implanted gastric balloon. Gastric distension/80 induced c-Fos throughout the nucleus of the solitary tract, with the densest labeling observed within 300 μm of the rostral pole of the area postrema. This area was analysed quantitatively following several manipulations. Gastric distension/80 induced a mean of 724 c-Fos-immunoreactive nuclei per section. Following subdiaphragmatic vagotomy plus Distention (vagotomy/80), the induction of c-Fos-immunoreactive nuclei was reduced to 293 per section, while spinal transection at T2 plus Distention (spinal transection/80) induced a mean of 581 nuclei per nucleus of the solitary tract section. Gastric distension/80 and vagotomy/80 induced minimal c-Fos in the T8–T10 spinal cord (50 nuclei/section), but spinal transection/80 induced 200 nuclei per section. Repetitive bolus injections of norepinephrine produced transient pressor responses mimicking the pressor response produced by gastric distension/80. This manipulation induced minimal c-Fos in the nucleus of the solitary tract and none in the spinal cord. It is concluded that noxious visceral input via parasympathetic vagal afferents, and to a lesser extent sympathetic afferents and the spinosolitary tract, contribute to gastric Distention-induced c-Fos in the nucleus of the solitary tract. The induction of c-Fos in the nucleus of the solitary tract is significantly greater than in the viscerotopic segments of the spinal cord, which is partially under tonic descending inhibition, but is not subject to modulation by vagal gastric afferents. Distention pressures produced by noxious gastric Distention are much greater than those produced during feeding, suggesting that c-Fos induction in the nucleus of the solitary tract to noxious Distention is not associated with physiological mechanisms of feeding and satiety. The large vagal nerve-mediated induction of c-Fos in the nucleus of the solitary tract following gastric distension suggests that parasympathetic afferents contribute to the processing of noxious visceral stimuli, perhaps by contributing to the affective–emotional component of visceral pain.
Fernando Azpiroz - One of the best experts on this subject based on the ideXlab platform.
-
Gastric wall tension determines perception of gastric Distention
Gastroenterology, 1999Co-Authors: Eleonora Distrutti, Fernando Azpiroz, Alfredo Soldevilla, Juan-r. MalageladaAbstract:Abstract Background & Aims: The primary mechanism that originates symptoms in response to gastric Distention remains undefined. The aim of this study was to determine which factor, whether intragastric volume, pressure, or wall tension, determines perception of gastric Distention. Methods: Healthy subjects underwent increasing gastric Distentions (2-minute duration at 5-minute intervals) either at fixed pressure levels using a conventional barostat (n = 10) or at fixed tension levels using a newly developed computerized tensostat (n = 12); perception was scored by a 0–6 scale. Distentions were performed during basal conditions (intravenous saline) and during gastric relaxation by glucagon administration (4.8 μg/kg intravenous bolus plus 9.6 μg · kg −1 · h −1 infusion). Results: Isobaric Distentions with the conventional barostat produced more intense perception during glucagon (95% ± 40% higher; P P P Conclusions: Gastric wall tension, but not intragastric volume, determines perception of gastric Distention, at least below nociception. GASTROENTEROLOGY 1999;116:1035-1042
-
the sympathetic nervous system modulates perception and reflex responses to gut Distention in humans
Gastroenterology, 1995Co-Authors: Paola Iovino, Fernando Azpiroz, Enrique Domingo, Juan-r. MalageladaAbstract:Abstract Background/Aims: Intestinal Distention induces perception and gut reflexes via sympathetic and vagal pathways, but the modulatory mechanisms of such responses remain obscure. The aim of this study was to determine the effects of sympathetic nervous activity on sympathetic and vagal reflexes as well as on intestinal and somatic perception. Methods: In 9 healthy volunteers, proximal duodenal Distentions were produced in 4-mL increments and hand transcutaneous electrical nerve stimulation was produced in 3-mA increments. Increasing stimuli of 1-minute duration were randomly performed at 10-minute intervals both with and without sympathetic activation (induced by means of lower body negative pressure). Intestinal and somatic perception was scored by specific questionnaires; vagal enterogastric and sympathetic intestinointestinal relaxatory reflexes were simultaneously measured by gastric and distal duodenal barostats. Results: Sympathetic activation significantly heightened perception of intestinal Distention without modifying perception of somatic stimuli (perception scores increased by 41% and −2%, respectively). The reflex responses to duodenal Distention significantly increased during sympathetic activation both in the stomach and in the intestine (relaxation increased by 91% and 69%, respectively; P
-
gastric tone determines the sensitivity of the stomach to Distention
Gastroenterology, 1995Co-Authors: Ricardo Notivol, Fernando Azpiroz, Jordi Serra, Benoit Coffin, Fermin Mearin, Juan-r. MalageladaAbstract:Abstract Background/Aims: Whether meal-related symptoms such as postcibal epigastric fullness and discomfort are caused by hypotonic gastric expansion or gastric hypertension is unknown. This study investigated whether symptoms in healthy individuals in response to gastric Distention are produced by gastric expansion or by an increase in intragastric pressure. Methods: Increasing gastric Distentions (for 5 minutes at 5-minute intervals) at fixed pressure levels (in 2-mm Hg increments) and at fixed volume levels (in 200-mL increments) were performed in 10 healthy subjects per group; perception was measured on a 0–6 scale. Distentions were performed during intravenous infusion of saline (basal) and during gastric relaxation by intravenous administration of glucagon (4.8-μg/kg bolus plus 9.6 μg · kg −1 · h −1 infusion). Results: The same distending pressures tested produced 30% ± 9% larger intragastric volumes and 80% ± 44% higher perception scores when the stomach was relaxed by glucagon ( P P
-
Perception and reflex responses to intestinal Distention in humans are modified by simultaneous or previous stimulation
Gastroenterology, 1995Co-Authors: Jordi Serra, Fernando Azpiroz, Juan-r. MalageladaAbstract:Abstract Background & Aims: Intestinal reflexes induced by Distention in dogs are facilitated by either simultaneous or previous Distentions. The aim of this study was to determine whether these phenomena also modulate the responses to intestinal Distention, particularly perception, in humans. Methods: Perception and intestinal relaxation were measured in 11 healthy subjects in response to increasing jejunal balloon Distentions tested (by stimulus-response trials) alone, as control, and with conditioning Distentions applied either simultaneously, immediately (10 seconds) before at the same site, or immediately before and 5 cm distant. In 8 additional subjects, the effect of prolonged (90-minute) conditioning Distention was tested. Results: Conditioning had more pronounced effects on perception than on intestinal reflexes. Perception of intestinal Distention increased (by 84 ± 47%; P P
-
Sensorial and intestinointestinal reflex pathways in the human jejunum
Gastroenterology, 1991Co-Authors: Jean-michel Rouillon, Fernando Azpiroz, Juan-r. MalageladaAbstract:Abstract Using an intestinal barostat that maintains a constant pressure within an air-filled bag (12 cm long), the authors have previously shown reflex changes in intestinal tone induced by Distention. The aim of this study was to investigate the sensitivity and the responsiveness to such reflexes along the jejunum. Eight healthy volunteers were studied using two barostats operating simultaneously in the proximal and the distal jejunum (located 10 cm and 52 cm caudad to the ligament of Treitz, respectively). With one barostat, standardized Distentions (1 minute duration at 10-minute intervals in 4-mm Hg increments) were produced; with the other barostat, intestinal tone was measured as volumetric variations at constant pressure. Perception was scored (0–6) by a questionnaire. The proximal jejunum relaxed in response to Distention of the distal jejunum (mean ± SE, 40% + 7% Δvol; 5.1 + 0.1 perception score at the threshold for discomfort; P
Karen J Berkley - One of the best experts on this subject based on the ideXlab platform.
-
influence of endometriosis on visceromotor and cardiovascular responses induced by vaginal Distention in the rat
Pain, 2007Co-Authors: Hiroshi Nagabukuro, Karen J BerkleyAbstract:This study examined pseudoaffective responses elicited by vaginal Distention in urethane-anesthetized rats, and tested hypotheses that responses would be increased by endometriosis (ENDO) and vary with the estrous cycle. Three groups were studied: ENDO, shamENDO, and Naive. ENDO was induced by autotransplanting small pieces of uterine horn (or, for shamENDO, fat) on mesenteric arteries. Ten weeks later, rats in proestrus or metestrus were anesthetized with urethane. Distendable latex balloons were inserted into the vaginal canal. While an increasing series of vaginal Distentions was delivered, changes in electromyographic activity of the external oblique musculature (visceromotor response, VMR) and mean arterial pressure (pressor) responses were simultaneously measured. Vaginal Distention produced VMR and pressor responses in all groups. These responses were significantly greater in ENDO than in the other groups, and greater in proestrus than metestrus. Although the overall amount of cystic tissue was greater in proestrous than metestrous rats, there was no correlation between these amounts and VMR or pressor responses. Acute spinalization (T8-T9) and bilateral pelvic, but not hypogastric, neurectomy attenuated both VMR and pressor responses, supporting the hypothesis that vaginal nociception involves suprathoracic spinal processing of information conveyed by the pelvic nerve. These effects on VMR and pressor responses to vaginal Distention parallel behavioral escape responses to the same stimuli reported previously. The findings encourage continued use of VMR and pressor responses for further investigation of mechanisms underlying pain associated with ENDO and its potential treatment.