Intra-adrenal 11 beta-hydroxysteroid dehydrogenase plays a role in the regulation of corticosteroid secretion: an in vitro study in the rat.
The expression of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) has been demonstrated in the adrenal glands, but until now little attention has been paid on its possible physiologic action. In-situ perfused rat adrenals released under basal conditions, in addition to mineralo- and glucocorticoids, notable amounts of 11-dehydrocorticosterone (DH-B), the inactive form to which corticosterone (the main glucocorticoid in rodents) is converted by 11 beta-HSD. The addition to the perfusion medium of glycyrrhetinic acid, a specific inhibitor of 11 beta-HSD, strongly reduced DH-B release and simultaneously evoked a moderate rise in both mineralo- and glucocorticoid output. The bolus administration of ACTH strikingly enhanced mineralo- and glucocorticoid secretion, but it significantly depressed DH-B release Rat adrenal microsome preparations possessed 11 beta-HSD activity, that was inhibited by glycyrrhetinic acid. Conversely, ACTH was without any apparent effect, a finding indicating that the in vivo observed ACTH-induced inhibition of adrenal 11 beta-HSD activity is mediated by an indirect mechanism whose elucidation requires further investigation. In conclusion, our present findings suggest that adrenal 11 beta-HSD plays a role in the regulation of steroid secretion in rats under both basal and stimulated conditions.
Department of Anatomy, University of Padua, Italy.
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Musajo
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Neri
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Tortorella
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Mazzocchi
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Nussdorfer
D042842:11-beta-Hydroxysteroid Dehydrogenases; D000305:Adrenal Cortex Hormones / Q000378:metabolism*; D000311:Adrenal Glands / Q000201:enzymology* / Q000378:metabolism; D000450:Aldosterone / Q000378:metabolism; D000818:Animals; D006913:Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D011374:Progesterone / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D000305:Adrenal Cortex Hormones; D000450:Aldosterone; D011374:Progesterone; D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases