Lesion of the subfornical organ affects the haemotensive response to centrally administered relaxin in anaesthetized rats

Experiments were performed on anaesthetized, lactating rats to investigate the acute central actions of relaxin on blood pressure and vasopressin release. These results demonstrate a biphasic action of centrally administered relaxin, with the response to dorsally placed third ventricle relaxin being mediated by the subfornical organ, and the response to ventral injections associated with an unknown structure of the ventral third ventricle wall