Chromogranin A inhibits retinal dopamine release.
Chromogranin A (CGA), a peripherally active prohormone, is a soluble component in the secretory granules of many endocrine tissues and is cosecreted with their peptide or amine hormones. Using an antibody prepared against purified rat adrenal CGA, immunostaining was localized to the inner and outer plexiform layers of the rat retina and to selected ganglion cells. Exogenous CGA (purified from human adrenals) when applied to perfused rat retina potently inhibited the potassium-induced release of endogenous dopamine (DA). This action was dose-dependent, with an IC50 of 3 nM; at 100 nM CGA retinal DA release was completely abolished.
Gibson
C J
CJ
Department of Pathology, University of Western Ontario, London, Canada.
Munoz
D G
DG
D000818:Animals; D053379:Chromogranin A; D002864:Chromogranins / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D008297:Male; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000187:drug effects* / Q000378:metabolism
C506150:CHGA protein, human; D053379:Chromogranin A; D002864:Chromogranins; C506153:chromogranin A, rat; D011188:Potassium; D004298:Dopamine