Cyclic AMP generating systems in vertebrate retina: effects of histamine and an established retinal modulator, dopamine.
Histamine (HA), 1-1000 microM, significantly stimulated both basal and forskolin-activated cAMP generation in chicken and adult hen retina. The action of HA was reproduced by the selective H2-receptor agonists dimaprit and 4-methyl-histamine, but not by the selective H1-receptor agonist 2-thiazolylethylamine, and it was antagonized by the specific H2-receptor blockers cimetidine and tiotidine, but not by the H1-receptor blocker mepyramine. In parallel experiments, dopamine, an established retinal neuromodulator acting through the D1-type of receptor, also stimulated basal and forskolin-driven adenylate cyclase activity in homogenate of chicken retina. It is suggested that chicken retina contains HA H2-receptors which are positively coupled to the adenylate cyclase system.
Department of Biogenic Amines, Polish Academy of Sciences, Lodz.
J Z
JZ
Nowak
B
B
Sek
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000201:enzymology; D002645:Chickens; D002927:Cimetidine / Q000031:analogs & derivatives / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis*; D017259:Dimaprit; D004298:Dopamine / Q000494:pharmacology*; D005260:Female; D006632:Histamine / Q000494:pharmacology*; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology; D008297:Male; D008761:Methylhistamines / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D011969:Receptors, Histamine H1 / Q000187:drug effects / Q000502:physiology; D011970:Receptors, Histamine H2 / Q000187:drug effects / Q000502:physiology; D012160:Retina / Q000187:drug effects / Q000378:metabolism*; D013844:Thiazoles / Q000494:pharmacology; D013890:Thiourea / Q000494:pharmacology
D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D008761:Methylhistamines; D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2; D013844:Thiazoles; C029345:2-(2-aminoethyl)thiazole; D005576:Colforsin; C025566:4-methylhistamine; D002927:Cimetidine; D006632:Histamine; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; C023990:tiotidine; D013890:Thiourea; D011738:Pyrilamine; D004298:Dopamine; D017259:Dimaprit