INVITRO STUDY OF LABELED ALPHA-MSH DEGRADATION - ACTION OF PROTEOLYTIC INHIBITORS

Abstract

The velocity of labeled .alpha. MSH [.alpha.-melanotropin] degradation by rat tissues was studied at different temperatures. The appearance of damaged compounds from 125I .alpha. MSH is much lower at 4.degree. C than at 22 or 37.degree. C. Addition of proteolysis inhibitors (benzamidine or zymofren) reduces the damage velocity. Under standard conditions of temperature and buffer, the damage velocity is lower when the tissue homogenates are processed by heat (56.degree. C; 40 min). The existence of an enzymatic system capable of degradating radioiodine .alpha. MSH in the rat brain is discussed.