Effects of pineal indoles on corticosterone and aldosterone production by isolated rat adrenal cells.
Methoxytryptamine and melatonin inhibited ACTH-induced corticosterone output by isolated rat adrenal decapsular cells at a concentration of or exceeding 100 microM and 333 microM respectively. The other pineal indoles and arginine vasotocin did not show any inhibitory action. None of the indoles except methoxytryptamine, when tested at a concentration of 50 microM, was able to inhibit ACTH-stimulated aldosterone production by isolated rat adrenal capsular cells. The direct inhibitory effect of methoxytryptamine and melatonin was evident only when a pharmacological dose was used and therefore its physiological significance is not obvious. The locus of action of pineal indoles on the adrenal must therefore lie in the brain and/or the pituitary only under physiological conditions.
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Department of Biochemistry, Faculty of Medicine, Chinese University of Hong Kong, Shatin, N.T.
D008735:5-Methoxytryptamine / Q000494:pharmacology*; D000311:Adrenal Glands / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000450:Aldosterone / Q000096:biosynthesis*; D000818:Animals; D003345:Corticosterone / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D008550:Melatonin / Q000494:pharmacology*; D010870:Pineal Gland / Q000502:physiology*; D051381:Rats; D014363:Tryptamines / Q000494:pharmacology*; D014668:Vasotocin / Q000494:pharmacology*
D014363:Tryptamines; D008735:5-Methoxytryptamine; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D008550:Melatonin; D014668:Vasotocin; D003345:Corticosterone