Methionine enkephalin-induced changes in pigmentation of zebrafish (Cyprinidae, Brachydanio rerio) and related species and varieties, measured videodensitometrically. II. Pearl and gold danios.
In the fish Brachydanio albolineatus (pearl danio) MSH-induced darkening was similar to that of the B. rerio (zebrafish). However, they showed a greatly reduced response to methionine enkephalin (met-E) though these fish apparently have normal dermal melanophores. This suggests a central nature of met-E-induced darkening and on the other hand at least a partial lack of MSH production and/or release in response to met-E in these fish. Therefore this reduction in the response to met-E may involve a partial lack of opiate receptors in the cells that provide or stimulate MSH production in the pearl danio. In the B. rerio gold mutant met-E appeared to be able to induce production and/or release of MSH, but these fish have almost no dermal melanophores (except a few in the dorsal and tail fins) and therefore show no darkening in response to either MSH or met-E.
D000818:Animals; D002856:Chromatophores / Q000378:metabolism; D003530:Cyprinidae / Q000378:metabolism*; D003720:Densitometry; D004305:Dose-Response Relationship, Drug; D004744:Enkephalin, Methionine / Q000494:pharmacology*; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology; D008547:Melanophores / Q000378:metabolism; D009270:Naloxone / Q000494:pharmacology; D010858:Pigmentation / Q000187:drug effects*; D013045:Species Specificity
D009270:Naloxone; D004744:Enkephalin, Methionine; D009074:Melanocyte-Stimulating Hormones