The Experts below are selected from a list of 993 Experts worldwide ranked by ideXlab platform
Timothy S Gross - One of the best experts on this subject based on the ideXlab platform.
-
serum steroid hormones including 11 ketotestosterone 11 ketoandrostenedione and Dihydroprogesterone in juvenile and adult bonnethead sharks sphyrna tiburo
Journal of Experimental Zoology, 1999Co-Authors: Charles A. Manire, Timothy S Gross, L E L RasmussenAbstract:Previous studies in the placental viviparous bonnethead shark, Sphyrna tiburo, have correlated 17 β-estradiol, progesterone, testosterone, and dihydrotestosterone with reproductive events in both males and females. However, several key reproductive events, including implantation, maintenance of pregnancy, and parturition, did not correlate with these four steroid hormones. Therefore, the present study investigated three steroid hormones, 11-ketotestosterone, 11-ketoandrostenedione, and Dihydroprogesterone, which have demonstrably important roles in the reproductive cycles of teleosts. It was hypothesized that one or more of these three hormones would correlate with specific reproductive events in S. tiburo. Concurrently, developmental (growth and/or maturation) analyses of these three steroids plus 17 β-estradiol, progesterone, testosterone, and dihydrotestosterone were investigated in juvenile bonnethead sharks. Serum Dihydroprogesterone concentrations were highest in mature females and 11-ketotestosterone concentrations were highest in mature males. In mature females, 11-ketoandrostenedione levels were elevated from the time of mating, through six months of sperm storage and another four months of gestation. At parturition concentrations became significantly lower and remained lower until mating occurred again in another two to three months. Serum 11-ketotestosterone concentrations were the highest at implantation though not significant. In mature males, significantly elevated serum levels of Dihydroprogesterone occurred in April and May, near the start of annual testicular development. During growth in males, testosterone and dihydrotestosterone increased progressively and in females, testosterone increased progressively. At maturity in males, significant increases occurred in testosterone and 11-ketotestosterone concentrations while, in females, Dihydroprogesterone, 11-ketotestosterone, 17 β-estradiol, progesterone, testosterone, and dihydrotestosterone concentrations increased. This study shows that although testosterone may be the primary androgen in the bonnethead shark, other derived androgens may have important functions in growth, maturation, and reproduction. J. Exp. Zool. 284:595–603, 1999. © 1999 Wiley-Liss, Inc.
-
serum steroid hormones including 11 ketotestosterone 11 ketoandrostenedione and Dihydroprogesterone in juvenile and adult bonnethead sharks sphyrna tiburo
Journal of Experimental Zoology, 1999Co-Authors: Charles A. Manire, Timothy S Gross, L E L RasmussenAbstract:Previous studies in the placental viviparous bonnethead shark, Sphyrna tiburo, have correlated 17 β-estradiol, progesterone, testosterone, and dihydrotestosterone with reproductive events in both males and females. However, several key reproductive events, including implantation, maintenance of pregnancy, and parturition, did not correlate with these four steroid hormones. Therefore, the present study investigated three steroid hormones, 11-ketotestosterone, 11-ketoandrostenedione, and Dihydroprogesterone, which have demonstrably important roles in the reproductive cycles of teleosts. It was hypothesized that one or more of these three hormones would correlate with specific reproductive events in S. tiburo. Concurrently, developmental (growth and/or maturation) analyses of these three steroids plus 17 β-estradiol, progesterone, testosterone, and dihydrotestosterone were investigated in juvenile bonnethead sharks. Serum Dihydroprogesterone concentrations were highest in mature females and 11-ketotestosterone concentrations were highest in mature males. In mature females, 11-ketoandrostenedione levels were elevated from the time of mating, through six months of sperm storage and another four months of gestation. At parturition concentrations became significantly lower and remained lower until mating occurred again in another two to three months. Serum 11-ketotestosterone concentrations were the highest at implantation though not significant. In mature males, significantly elevated serum levels of Dihydroprogesterone occurred in April and May, near the start of annual testicular development. During growth in males, testosterone and dihydrotestosterone increased progressively and in females, testosterone increased progressively. At maturity in males, significant increases occurred in testosterone and 11-ketotestosterone concentrations while, in females, Dihydroprogesterone, 11-ketotestosterone, 17 β-estradiol, progesterone, testosterone, and dihydrotestosterone concentrations increased. This study shows that although testosterone may be the primary androgen in the bonnethead shark, other derived androgens may have important functions in growth, maturation, and reproduction. J. Exp. Zool. 284:595–603, 1999. © 1999 Wiley-Liss, Inc.
-
serum steroid hormones including 11 ketotestosterone 11 ketoandrostenedione and Dihydroprogesterone in juvenile and adult bonnethead sharks sphyrna tiburo
Journal of Experimental Zoology, 1999Co-Authors: Charles A. Manire, Timothy S Gross, L E L RasmussenAbstract:Previous studies in the placental viviparous bonnethead shark, Sphyrna tiburo, have correlated 17 beta-estradiol, progesterone, testosterone, and dihydrotestosterone with reproductive events in both males and females. However, several key reproductive events, including implantation, maintenance of pregnancy, and parturition, did not correlate with these four steroid hormones. Therefore, the present study investigated three steroid hormones, 11-ketotestosterone, 11-ketoandrostenedione, and Dihydroprogesterone, which have demonstrably important roles in the reproductive cycles of teleosts. It was hypothesized that one or more of these three hormones would correlate with specific reproductive events in S. tiburo. Concurrently, developmental (growth and/or maturation) analyses of these three steroids plus 17 beta-estradiol, progesterone, testosterone, and dihydrotestosterone were investigated in juvenile bonnethead sharks. Serum Dihydroprogesterone concentrations were highest in mature females and 11-ketotestosterone concentrations were highest in mature males. In mature females, 11-ketoandrostenedione levels were elevated from the time of mating, through six months of sperm storage and another four months of gestation. At parturition concentrations became significantly lower and remained lower until mating occurred again in another two to three months. Serum 11-ketotestosterone concentrations were the highest at implantation though not significant. In mature males, significantly elevated serum levels of Dihydroprogesterone occurred in April and May, near the start of annual testicular development. During growth in males, testosterone and dihydrotestosterone increased progressively and in females, testosterone increased progressively. At maturity in males, significant increases occurred in testosterone and 11-ketotestosterone concentrations while, in females, Dihydroprogesterone, 11-ketotestosterone, 17 beta-estradiol, progesterone, testosterone, and dihydrotestosterone concentrations increased. This study shows that although testosterone may be the primary androgen in the bonnethead shark, other derived androgens may have important functions in growth, maturation, and reproduction. J. Exp. Zool. 284:595-603, 1999.
Hironobu Sasano - One of the best experts on this subject based on the ideXlab platform.
-
progesterone metabolism in human leukemic monoblast u937 cells
Endocrine Journal, 2002Co-Authors: Takashi Suzuki, Barbara A. Murry, Andrew D. Darnel, Hironobu SasanoAbstract:Progesterone markedly inhibitis the functions of human macrophages and T lymphocytes, and acts as an immunosuppressant during pregnancy. It is important to examine progesterone metabolites to understand the overall bioactive properties of this sex steroid. However, progesterone metabolism has not been examined in human immune cells. The human leukemic monoblast U937 cell line exhibits monocytic lineage and provides a valuable model to analyze monocyte-macrophage differentiation. Therefore, in this study, we analyzed progesterone metabolism in U937 cells by thin-layer chromatography. Progesterone was metabolized to 5α-pregnan-3β,6α-diol-20-one via 5α-Dihydroprogesterone and 5α-pregnan-3β-ol-20-one, and 5α-pregnan-3β,20α-diol was also detected as a final metabolic product via 20α-Dihydroprogesterone and 5α-pregnan-20α-ol-3-one. 5α-reduction (5α-reductase type 1) and 20α-reduction were involved in the first step of metabolism. To identify the enzyme responsible for the 20α-reduction, we screened an U937 cDNA library, and obtained a clone (1.2 kb), which was identical to the human hepatic bile acid-binding protein or 20α-hydroxysteroid dehydrogenase (20α-HSD). 293 cells transfected with this cDNA demonstrated marked 20α-reduction of progesterone to 20αDHP, but 20α-oxidative, 3α-HSD or 17β-HSD activity was found to be negligible. In experimental animals, the importance of 20α-HSD has been reported to be involved in the protection of immune cells from the toxic effects of progesterone. Therefore, our present data suggest that 20α-HSD plays an important role in the reguation of progesterone actions in human immune cells.
-
Progesterone metabolism in human leukemic monoblast U937 cells.
Endocrine journal, 2002Co-Authors: Takashi Suzuki, Barbara A. Murry, Andrew D. Darnel, Hironobu SasanoAbstract:Progesterone markedly inhibits the functions of human macrophages and T lymphocytes, and acts as an immunosuppressant during pregnancy. It is important to examine progesterone metabolites to understand the overall bioactive properties of this sex steroid. However, progesterone metabolism has not been examined in human immune cells. The human leukemic monoblast U937 cell line exhibits monocytic lineage and provides a valuable model to analyze monocyte-macrophage differentiation. Therefore, in this study, we analyzed progesterone metabolism in U937 cells by thin-layer chromatography. Progesterone was metabolized to 5alpha-pregnan-3beta,6alpha-diol-20-one via 5alpha-Dihydroprogesterone and 5alpha-pregnan-3beta-ol-20-one, and 5alpha-pregnan-3beta,20alpha-diol was also detected as a final metabolic product via 20alpha-Dihydroprogesterone and 5alpha-pregnan-20alpha-ol-3-one. 5alpha-reduction (5alpha-reductase type 1) and 20alpha-reduction were involved in the first step of metabolism. To identify the enzyme responsible for the 20alpha-reduction, we screened an U937 cDNA library, and obtained a clone (1.2 kb), which was identical to the human hepatic bile acid-binding protein or 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD). 293 cells transfected with this cDNA demonstrated marked 20alpha-reduction of progesterone to 20alphaDHP, but 20alpha-oxidative, 3alpha-HSD or 17beta-HSD activity was found to be negligible. In experimental animals, the importance of 20alpha-HSD has been reported to be involved in the protection of immune cells from the toxic effects of progesterone. Therefore, our present data suggest that 20alpha-HSD plays an important role in the regulation of progesterone actions in human immune cells.
Junichi Mori - One of the best experts on this subject based on the ideXlab platform.
-
secretion of progesterone and 20α Dihydroprogesterone during the estrous cycle in goats
Steroids, 1994Co-Authors: Tsutomu Sawada, Hiromichi Tamada, Masahiro Hou, Junichi MoriAbstract:The secretion of progesterone and 20 alpha-Dihydroprogesterone (20 alpha-DHP) during the estrous cycle and the effects of prostaglandin F2 alpha (PGF2 alpha) and 20 alpha-DHP on the secretion of these two steroids during the midluteal phase in goats were studied. The mean progesterone concentration in the peripheral plasma was extremely low ( 1 after day 2 of estrus, but decreased and fell to < 1 during the last 3 days of the cycle. An injection of 3 mg of PGF2 alpha decreased the secretion of progesterone within 30 min, but affected the secretion of 20 alpha-DHP little until 2 h. The ratio of progesterone to 20 alpha-DHP fell to < 1 after 24 h. Three of the five goats given such an injection came into estrus within 2 days, and the other two came into estrus within 3 days. An injection of 15 mg of 20 alpha-DHP did not affect progesterone secretion or the estrous cycle length. These results indicate that in the goat after estrus, there is much 20 alpha-DHP in the peripheral plasma. Progesterone may be catabolized to the biologically inactive steroid, 20 alpha-DHP, during luteolysis.
-
secretion of progesterone and 20α Dihydroprogesterone during pregnancy in goats
Steroids, 1994Co-Authors: Tsutomu Sawada, Hiromichi Tamada, Toshiko Nakatani, Junichi MoriAbstract:Abstract The relationships between the secretion of progesterone and 20α-Dihydroprogesterone and the sites of their production in pregnant goats were investigated. The progesterone concentration in the peripheral plasma increased after the goats mated, and was high from day 10 to day 140 of pregnancy. The 20α-Dihydroprogesterone concentration increased gradually from day 0 to day 140 after mating. The progesterone concentration before parturition decreased rapidly on day 1 prepartum, but the 20α-Dihydroprogesterone concentration remained high until the day of parturition and then began to fall. The ratio of progesterone to 20α-Dihydroprogesterone decreased and fell to less than one on day 1 prepartum. The plasma concentrations of progesterone in ovarian vein and of 20α-Dihydroprogesterone in the ovarian vein, umbilical vein, and umbilical artery were higher than those in the jugular vein. The ratio of progesterone to 20α-Dihydroprogesterone in placental tissue was less than one. These results suggest that in pregnant goats the main production site is the ovary for progesterone and the ovary and feto-placental unit for 20α-Dihydroprogesterone, and 20α-Dihydroprogesterone may take help to regulate progesterone production within the ovary and the feto-placental unit (Steroids 59: 468–471, 1994)
W. Mcintyre Burnham - One of the best experts on this subject based on the ideXlab platform.
-
The effects of 5a-Dihydroprogesterone and benzyl alcohol in amygdala-kindled seizures
Clinical Neurophysiology, 2019Co-Authors: W. Mcintyre BurnhamAbstract:5a-Dihydroprogesterone (DHP), the primary metabolite of progesterone, has anti-seizure properties. The present study investigated the time-course of the anti-seizure effects of 5a-Dihydroprogesterone, injected via the IP route, in an animal model of human drug-resistant seizures – the amygdala-kindling model. Female, Wistar amygdala-kindled rats were injected intraperitoneally (I.P.) with 30 mg/kg of DHP, and the suppression of focal electrographic seizures and secondarily generalized convulsions was tested from 10 to 150 min post-injection. DHP was dissolved in the “benzyl vehicle” (benzyl alcohol: benzyl benzoate: cottonseed oil, 1.5:1.5:7, v:v:v), DHP in the benzyl vehicle demonstrated good anti-seizure effects at two time points: (1) immediately (10–20 min) after injection, and (2) at about 130 min after injection. Both generalized and focal seizures were suppressed at the early time point, but only generalized seizures were suppressed at 130 min. Ataxia was seen at the earlier time point, but not at the later time-point. When a vehicle control was done, we observed both focal and generalized seizure suppression at the early time point (10–20 min) in the absence of DHP. A subsequent examination revealed that benzyl alcohol was the only active ingredient in the benzyl vehicle, and that it has clear anti-seizure effects. No seizure suppression was seen with benzyl alcohol at later time points. In conclusion, the anti-seizure effects seen shortly after injection may relate to either DHP or benzyl alcohol, whereas the seizure suppression seen at later time points seems to relate to DHP, or perhaps a DHP metabolite. A future study might attempt to establish a time-course for DHP metabolism in the rat and to determine what compound relates to these late-developing effects. This study was supported by EpLink – The Epilepsy Research Program of the Ontario Brain Institute.
-
The Anticonvulsant Effects of Progesterone and 5α-Dihydroprogesterone on Amygdala-kindled Seizures in Rats
Epilepsia, 2003Co-Authors: Deborah Lonsdale, W. Mcintyre BurnhamAbstract:Summary: Purpose: Progesterone has been shown to be anticonvulsant in several animal seizure models. The purpose of the present study was to investigate the anticonvulsant actions of progesterone and its primary metabolite 5α-Dihydroprogesterone in the amygdala kindling model. Methods: Female Wistar rats were implanted in the right basolateral amygdala with a long-term, bipolar electrode. The subjects were kindled to 30 stage 5 seizures and stability tested. Multiple doses of progesterone and 5α-Dihydroprogesterone were then tested for anticonvulsant activity against focal electrographic and generalized convulsive kindled seizures. The time course of progesterone's anticonvulsant action also was examined. Results: Progesterone had a median effective dose (ED50) of 103 mg/kg against generalized convulsions at 15 min after injection. Subjects were not sedated at the time of seizure testing, although sedation developed later (40–60 min after injection). In time-course experiments, it was found that 120 mg/kg of progesterone caused complete suppression of the generalized convulsion from 20 to 160 min after injection. Suppression of the focal discharge also was seen in some animals between 20 and 160 min. 5α-Dihydroprogesterone had an ED50 of 2.9 mg/kg against generalized kindled convulsions and an ED50 of 4.3 mg/kg against focal afterdischarge 15 min after injection. 5α-Dihydroprogesterone did not produce sedation 15 min after injection, or at any later time interval. Conclusions: Progesterone is anticonvulsant only at high doses when tested against amygdala kindled seizures. 5α-Dihydroprogesterone is considerably more potent than progesterone. At low, nonsedative doses, it was effective against both the kindled amygdala focal afterdischarge and the generalized convulsion.
Takashi Suzuki - One of the best experts on this subject based on the ideXlab platform.
-
progesterone metabolism in human leukemic monoblast u937 cells
Endocrine Journal, 2002Co-Authors: Takashi Suzuki, Barbara A. Murry, Andrew D. Darnel, Hironobu SasanoAbstract:Progesterone markedly inhibitis the functions of human macrophages and T lymphocytes, and acts as an immunosuppressant during pregnancy. It is important to examine progesterone metabolites to understand the overall bioactive properties of this sex steroid. However, progesterone metabolism has not been examined in human immune cells. The human leukemic monoblast U937 cell line exhibits monocytic lineage and provides a valuable model to analyze monocyte-macrophage differentiation. Therefore, in this study, we analyzed progesterone metabolism in U937 cells by thin-layer chromatography. Progesterone was metabolized to 5α-pregnan-3β,6α-diol-20-one via 5α-Dihydroprogesterone and 5α-pregnan-3β-ol-20-one, and 5α-pregnan-3β,20α-diol was also detected as a final metabolic product via 20α-Dihydroprogesterone and 5α-pregnan-20α-ol-3-one. 5α-reduction (5α-reductase type 1) and 20α-reduction were involved in the first step of metabolism. To identify the enzyme responsible for the 20α-reduction, we screened an U937 cDNA library, and obtained a clone (1.2 kb), which was identical to the human hepatic bile acid-binding protein or 20α-hydroxysteroid dehydrogenase (20α-HSD). 293 cells transfected with this cDNA demonstrated marked 20α-reduction of progesterone to 20αDHP, but 20α-oxidative, 3α-HSD or 17β-HSD activity was found to be negligible. In experimental animals, the importance of 20α-HSD has been reported to be involved in the protection of immune cells from the toxic effects of progesterone. Therefore, our present data suggest that 20α-HSD plays an important role in the reguation of progesterone actions in human immune cells.
-
Progesterone metabolism in human leukemic monoblast U937 cells.
Endocrine journal, 2002Co-Authors: Takashi Suzuki, Barbara A. Murry, Andrew D. Darnel, Hironobu SasanoAbstract:Progesterone markedly inhibits the functions of human macrophages and T lymphocytes, and acts as an immunosuppressant during pregnancy. It is important to examine progesterone metabolites to understand the overall bioactive properties of this sex steroid. However, progesterone metabolism has not been examined in human immune cells. The human leukemic monoblast U937 cell line exhibits monocytic lineage and provides a valuable model to analyze monocyte-macrophage differentiation. Therefore, in this study, we analyzed progesterone metabolism in U937 cells by thin-layer chromatography. Progesterone was metabolized to 5alpha-pregnan-3beta,6alpha-diol-20-one via 5alpha-Dihydroprogesterone and 5alpha-pregnan-3beta-ol-20-one, and 5alpha-pregnan-3beta,20alpha-diol was also detected as a final metabolic product via 20alpha-Dihydroprogesterone and 5alpha-pregnan-20alpha-ol-3-one. 5alpha-reduction (5alpha-reductase type 1) and 20alpha-reduction were involved in the first step of metabolism. To identify the enzyme responsible for the 20alpha-reduction, we screened an U937 cDNA library, and obtained a clone (1.2 kb), which was identical to the human hepatic bile acid-binding protein or 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD). 293 cells transfected with this cDNA demonstrated marked 20alpha-reduction of progesterone to 20alphaDHP, but 20alpha-oxidative, 3alpha-HSD or 17beta-HSD activity was found to be negligible. In experimental animals, the importance of 20alpha-HSD has been reported to be involved in the protection of immune cells from the toxic effects of progesterone. Therefore, our present data suggest that 20alpha-HSD plays an important role in the regulation of progesterone actions in human immune cells.