Histamine-mediated regulation of cAMP levels and inositol phosphate metabolism in isolated rabbit retina.
In pieces of the rabbit retina, histamine (HI) had no significant effect on cAMP accumulation; however, HI inhibited forskolin-evoked accumulation of the nucleotide. Mepyramine (H1-antagonist) was without effect, while cimetidine (H2-antagonist) antagonized the HI action. Dimaprit (H2-agonist) mimicked the HI action, however its action was not significantly affected by H2-antagonists. Since phosphodiesterase (PDE) inhibitors prevented the HI action it is suggested that HI-induced inhibition of the forskolin effect results from HI-induced activation of cAMP breakdown. The muscarinic agonist carbachol, and to a lesser extent HI, both increased [3H]inositol incorporation and intensified accumulation of [3H]inositol phosphates in the rabbit retina.
Nowak
J Z
JZ
Department of Biogenic Amines, Polish Academy of Sciences, Lodz-1, Poland.
Sek
B
B
Szkiel
B
B
D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D006632:Histamine / Q000494:pharmacology*; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000378:metabolism; D011817:Rabbits; D011969:Receptors, Histamine H1 / Q000187:drug effects / Q000378:metabolism; D012160:Retina / Q000187:drug effects* / Q000378:metabolism
D007295:Inositol Phosphates; D011969:Receptors, Histamine H1; D005576:Colforsin; D006632:Histamine; D002217:Carbachol; D000242:Cyclic AMP