Identification of epinephrine and phenylethanolamine N-methyltransferase activity in rat retina.
Epinephrine (E) and phenylethanolamine N-methyltransferase (PNMT) are endogenous to the rat retina. The retinal enzyme shows substrate specificity and inhibitor sensitivity similar to the PNMT of brain. The E system in the retina may be part of a functional adrenergic system, because amine metabolism of dopamine-containing amacrine cells is inhibited by alpha 2 agonists and stimulated by alpha 2 antagonists.
D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D003907:Dexamethasone / Q000494:pharmacology; D004298:Dopamine / Q000032:analysis; D004837:Epinephrine / Q000032:analysis*; D007700:Kinetics; D009638:Norepinephrine / Q000032:analysis; D010625:Phenylethanolamine N-Methyltransferase / Q000378:metabolism*; D051381:Rats; D012160:Retina / Q000032:analysis / Q000201:enzymology* / Q000254:growth & development; D013379:Substrate Specificity
D003907:Dexamethasone; D010625:Phenylethanolamine N-Methyltransferase; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine