Calcium-dependent irreversible effect of ionophore A23187 on melanophores.
The calcium ionophore, A231187, induces a Ca2+ -dependent movement (dispersion) of melanosomes within skin melanophores of the lizard, Anolis carolinensis, in vitro. The effects of A23187 are irreversible, since after repeated rinsing of the skins in the absence of the ionophore they will always darken in Ringer containing Ca2+ but will immediately lighten when transferred to Ca2+ -free Ringer. These results suggest that the ionophore is irreversibly localized to the melanophore membrane and that its melanosome-dispersing effect is continuously dependent upon extracellular calcium.
Hadley
M E
ME
Department of Anatomy, Arizona Health Sciences, College of Medicine, Tucson 85724.
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology; D008116:Lizards; D008544:Melanocytes / Q000166:cytology* / Q000187:drug effects; D008547:Melanophores / Q000166:cytology* / Q000187:drug effects; D012016:Reference Values; D012867:Skin / Q000166:cytology / Q000187:drug effects; D000521:alpha-MSH / Q000494:pharmacology
D000001:Calcimycin; D000521:alpha-MSH; D007545:Isoproterenol; D002118:Calcium