Vasopressin and angiotensin II are absent but spontaneously reappear in solitary hypothalamic neurons of the homozygous Brattleboro rat

Abstract

The homozygous Brattleboro rat (di/di) synthesizes a vasopressin (VP) precursor with a different C-terminus, which is not packaged in granules. In addition, the expression of a coexisting peptide, angiotensin II (Ang II), is disturbed. During postnatal life a small but increasing number of solitary post-mitotic hypothalamic neurons of the di/di rat undergoes a switch to a genuine heterozygous phenotype. Here we report the reappearance of Ang II in these heterozygous cells, which suggests that for the expression of Ang II a normal VP precursor is required. Based upon the present study and literature data it is proposed that at the level of the endoplasmic reticulum a compartmentalization of the synthesis of various peptide precursor occurs.