Light-induced pigment aggregation in cultured fish melanophores: spectral sensitivity and inhibitory effects of theophylline and cyclic adenosine-3',5'-monophosphate.
About 20% of xiphophorin fish (Xiphophorus maculatus) dermal melanophores which were cultured in monolayer for 5 to 10 days responded to light directly, exhibiting reversible melanosome aggregation within a few minutes. In order to determine the spectral sensitivity for the light-response, absorbance changes due to the light-induced melanosome aggregation were measured on single melanophores in a range of wavelengths from 370 to 550 nm using a recording microspectrophotometer. The melanophores showed maximum sensitivity to a wavelength of about 410 nm and very little to those longer than 500 nm. 10(-4) to 10(-2) M theophylline and 10(-4) M cAMP had inhibitory effects on the light-response.
D000818:Animals; D002449:Cell Aggregation / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000494:pharmacology*; D005399:Fishes; D008027:Light; D008544:Melanocytes; D008547:Melanophores / Q000187:drug effects / Q000528:radiation effects*; D013053:Spectrophotometry; D013806:Theophylline / Q000494:pharmacology*
D013806:Theophylline; D000242:Cyclic AMP