STANDARDIZATION AND EVALUATION OF A SENSITIVE AND CONVENIENT ASSAY FOR MELANOCYTE-STIMULATING HORMONE USING ANOLIS SKIN IN VITRO

Abstract

SUMMARY A method is described for the quantitative bioassay of melanocytestimulating hormone (MSH) activity using the skin of the lizard Anolis carolinensis in vitro. The colour changes were registered photoelectrically as changes in reflexion of green monochromatic light. Synthetic α-MSH (CIBA-Geigy Ltd) was used as standard. The method can detect MSH activity at a concentration down to 0·01–0·05 ng α-MSH/ml, and allows the detection of MSH activity in normal rat plasma. The mean precision of the assay λ is about 0·13. This assay thus combines high sensitivity with good precision, and is also comparatively rapid, easy to handle and inexpensive.