Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.1 (adenylate cyclase)
 19,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of cAMP in the control of follicular steroidogenesis of amago salmon (Oncorhynchus rhodurus) was studied using in vitro incubation of isolated thecal and granulosa layers. Particular attention was paid to the role of cAMP in the shift in the steroidogenic responses of follicle layers to gonadotropin (partially purified chum salmon gonadotropin, SGA) during oogenesis. First, the effects of SGA and forskolin, an activator of adenylate cyclase, on intratissue accumulation of cAMP were determined using isolated thecal and granulosa layers from various stages of development. Regardless of the stage of development, SGA and forskolin stimulated cAMP formation in both layers within 1 hr of incubation. Second, the effects of SGA, forskolin, dibutyryl cAMP, and inhibitors of phosphodiesterase on testosterone and 17 alpha-hydroxyprogesterone production by thecal layers and on the activities of aromatase and 20 beta-hydroxysteroid dehydrogenase in granulosa layers from follicles of various developmental stages were investigated. All steroidogenic actions of SGA were mimicked by those agents known to raise the cellular level of cAMP. These results provide evidence that the steroidogenic actions of gonadotropin in both thecal and granulosa layers depend on increased intracellular cAMP, and they further suggest that a change in cellular events at a step(s) subsequent to cAMP production is involved in regulating the shift in the steroidogenic responses of follicle layers to gonadotropin.
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PMID:Involvement of 3',5'-cyclic adenosine monophosphate in the control of follicular steroidogenesis of amago salmon (Oncorhynchus rhodurus). 284 8

Human placenta and fetal membranes contain two types of 11beta-hydroxysteroid dehydrogenase (11beta-HSD). 11Beta-HSD1 interconverts cortisol and cortisone and is the predominant isoform found in the fetal membranes. 11Beta-HSD2, which predominates in the placenta syncytiotrophoblast, converts cortisol to cortisone. It has been proposed that placental 11beta-HSD protects the fetus from high levels of maternal glucocorticoids. In this study, cultured term human placental and chorionic trophoblasts were used to examine the regulation of 11beta-HSD1 and 11beta-HSD2 activities and mRNA expression by progesterone, estrogen, and activators of adenylate cyclase (forskolin) and protein kinase C (phorbol 12-myristate 13-acetate, PMA). Placental trophoblast displayed mainly type 2 oxidase activities. 11Beta-HSD in the chorionic trophoblast was exclusively an 11beta-HSD1 reductase. Progesterone (0.001-1 microM) inhibited 11beta-HSD2 activity in a dose-dependent fashion. Inhibition of endogenous progesterone production with trilostane enhanced 11beta-HSD2 activity. The inhibitory effect of progesterone on 11beta-HSD2 activity was not reversed by the progesterone receptor antagonists RU-486 or onapristone. Progesterone (1 microM) also reduced levels of 11beta-HSD2 mRNA, an effect that was attenuated by both RU-486 and onapristone. Estradiol (1 microM) inhibited type 2 oxidase activity as well. Activation of adenylate cyclase by forskolin (100 microM) up-regulated both 11beta-HSD2 activity and mRNA expression; there was no effect of PMA (1 microM) on 11beta-HSD2. 11Beta-HSD1 reductase activity was unaffected by progesterone, estrogen, forskolin, or PMA in either the placental or chorionic trophoblasts. We conclude that both progesterone and estrogen are inhibitors of 11beta-HSD2 activity in term human placenta in vitro. Levels of 11beta-HSD2 activity and mRNA are increased by activation of the cAMP pathway. Progesterone also suppresses levels of 11beta-HSD2 mRNA.
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PMID:Regulation of 11beta-hydroxysteroid dehydrogenase type 2 by progesterone, estrogen, and the cyclic adenosine 5'-monophosphate pathway in cultured human placental and chorionic trophoblasts. 962 96