Fate of human corticotrophin immediately after intravenous administration to the rat.

The distribution and degradation of tritium-labelled human 1-39 corticotrophin have been studied after intravenous administration to the rat. Within 5 min of injection of single major metabolite, 3-39 corticotrophin, appears in the circulation. This metabolite, however, has only 3.6% of the steroidogenic potency of 1-39 corticotrophin and the evidence suggests that it is formed in muscle and skin. By 5 min, extensive degradation had occurred in all the major tissues in the body (muscle, skin, liver, kidney, gut).