Calcium Requirement for Melanophore-Stimulating Hormone Action on Melanophores

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Science  03 Sep 1971:
Vol. 173, Issue 4000, pp. 923-925
DOI: 10.1126/science.173.4000.923


The calcium ion is specifically required for the action of melanophorestimulating hormone on melanosome dispersion within lizard (Anolis carolinensis) melanophores in vitro. The response to this hormone is directly related to the concentration of the Ca2+ ion. Lithium, choline, rubidium, and cesium will replace the sodium and potassium of Ringer solution if Ca2+ is present. Calcium ions are not required for melanosome dispersion itself, since theophylline or dibutyryl cyclic adenosine monophosphate reversibly darkens lizard skins in the absence of calcium.