The role of calcium in MSH stimulated melanosome dispersion.
We have examined the role of the calcium ion in the response of the melanophores of the lizard, Anolis carolinensis to alpha-melanocyte stimulating hormone (alpha-MSH) by a rate method which allows kinetic analysis of melanosome dispersion. Dose-response curves to alpha-MSH were compared in the presence of different calcium concentrations, and Schild regression plots were constructed. An avidly binding analogue of alpha-MSH, Nle4-D-Phe7-alpha-MSH, was used to demonstrate kinetically the involvement of calcium in the melanophore response both for MSH receptor binding and the subsequent transduction of the MSH signal across the melanophore membrane.
Lucas
A M
AM
Department of Dermatology, University of Newcastle upon Tyne, England.
Thody
A J
AJ
Shuster
S
S
D000818:Animals; D002118:Calcium / Q000502:physiology*; D003000:Clonidine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007811:Lanthanum / Q000494:pharmacology; D008116:Lizards; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology*; D008544:Melanocytes / Q000187:drug effects*; D011979:Receptors, Pituitary Hormone / Q000378:metabolism; D000521:alpha-MSH / Q000031:analogs & derivatives / Q000494:pharmacology
D011979:Receptors, Pituitary Hormone; D000521:alpha-MSH; D007811:Lanthanum; C027756:MSH, 4-Nle-7-Phe-alpha-; C029446:MSH receptor; D009074:Melanocyte-Stimulating Hormones; D003000:Clonidine; D002118:Calcium