Pressor action of centrally perfused angiotensin II in rats with hereditary hypothalamic diabetes insipidus.

A method was devised for the perfusion of the cerebral ventricles in conscious rats. Using this method a basal secretion rate of 15 +/- 3 pg of immunoreactive angiotensin II per min was calculated. This material was suggested to be of extrarenal origin. In comparison to findings in normal Long-Evans rats, pressor responses to intraventricular perfusions of angiotensin II were reduced in rats heterozygous for hypothalamic diabetes insipidus and virtually absent in rats homozygous for the hypothalamic deficiency whether they were treated with vasopressin or not. The pressor response to intraventricular angiotensin II is suggested to be related to the release of vasopressin.