Staining of magnocellular neurons of the supraoptic and paraventricular nuclei with vasopressin anti-idiotype antibody: a potential method for receptor immunocytochemistry.

A vasopressin anti-idiotype antibody was generated by immunization with a primary anti-vasopressin IgG. This antibody was capable of immunostaining vasopressinergic neurons in the supraoptic and paraventricular nuclei of the hypothalami of normal and Brattleboro rats. Staining was eliminated by preabsorption or coincubation of the antibody with a vasopressin binding protein prepared from rat neural membranes. The anti-idiotype also inhibited binding of [3H]vasopressin to this neural membrane protein in a dose-dependent manner. These experiments suggest that the anti-idiotype antibody recognizes a receptor associated with vasopressinergic neurons.