EFFECT OF MELANOPHORE-STIMULATING HORMONE ON HUMAN DARK ADAPTATION

Abstract

A preparation of melanophore-stimulating hormone (MSH) obtained from porcine anterior pituitary glands was found to produce no effect on the course of dark adaptation in normal human subjects, when injected subcutaneously in doses of 185 or 550 I.U.A partially purified MSH was prepared from bovine posterior pituitary glands by Hanaoka's modification of Stehle's method. It was assayed by a skin reflectance method in hypophysectomized frogs. When administered subcutaneously in a dose of 500 I.U., this material also failed to affect the course of dark adaptation in six normal subjects of Caucasian ancestry and six of Japanese ancestry.These results are compared with those of other investigators, and the disagreements are attributed to differences in apparatus and technique of measurement of dark adaptation. It is concluded that exogenous MSH does not affect dark adaptation in normal subjects.