Substances resembling C-terminal vasopressin fragments are present in the brain but not in the pituitary gland

Abstract

In order to investigate the endogenous occurrence of vasopressin fragments that have previously been found to be generated in vitro by brain peptidases and to have highly potent central activity, extracts of hypothalamus, hippocampus and the pituitary gland were fractionated by high pressure liquid chromatography and analyzed by radioimmunoassay systems with different specificities. Substances that were immunologically and chromatographically similar to synthetic C-terminal vasopressin fragments were detected in brain tissue in different amounts, but were virtually absent in the pituitary gland. It is suggested that these components may represent endogenous vasopressin metabolites. The preferential presence in brain supports a selectively central function of these peptides