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Stimulatory Effect of Histamine on Cyclic AMP Formation in Chick Pineal Gland
Author(s) -
Nowak Jerzy Z.,
Sek Barbara
Publication year - 1994
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1994.63041338.x
Subject(s) - dimaprit , thioperamide , ibmx , mepyramine , medicine , endocrinology , agonist , histamine h3 receptor , forskolin , histamine , chemistry , cimetidine , biology , receptor , histamine h2 receptor , pharmacology , antagonist , stimulation
Histamine (HA) potently stimulated cyclic AMP accumulation in intact pineal glands taken from light‐exposed chicks. The action of HA was stronger in the presence of forskolin and the phosphodiesterase inhibitor 3‐isobutyl‐1‐methylxanthine (IBMX). The effect of HA was mimicked by HA H 1 ‐ and H 2 ‐receptor‐selective agonists in the following order of potency: HA > 4‐methylhistamine (H 2 ) > 2‐methylhistamine (H 1 ) > 2‐thiazolylethylamine (H 1 ) ≫ dimaprit (H 2 ). The HA H 3 ‐receptor‐selective agonist ( R )α‐methylhistamine was poorly active. The effect of HA was antagonized by selective H 2 ‐receptor blockers (tiotidine > oxmetidine > cimetidine = ranitidine) and was not significantly affected by the selective H 1 ‐ and H 3 ‐receptor blockers mepyramine and thioperamide. A detailed analysis of an antagonistic action of ranitidine (versus HA) revealed a noncompetitive mode of action of the H 2 blocker. The stimulatory action of the H 1 agonist 2‐thiazolylethylamine (both under basal conditions and in the presence of forskolin or IBMX) was not significantly influenced by three H 1 ‐receptor‐selective blockers (mepyramine, triprolidine, and diphenhydramine), but it was totally counteracted by ranitidine. Using accepted selective agonists and antagonists of the HA H 1 , H 2 , and H 3 receptor we were unable to identify clearly the receptor subtype mediating the HA action on the cyclic AMP‐generating system of the chick pineal. It is suggested that the receptor under consideration may represent either an H 2 ‐like (in terms of mammalian criteria) or avian‐specific HA receptor. The data suggest that HA may be considered a modulator of the pineal activity in chicks.