PVN lesions prevent the endothelin 1-induced increase in arterial pressure and vasopressin

Departments of Medicine and Physiology, Wayne State University School of Medicine and John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan 48201 Endothelin (ET) acts within the central nervous system to increase arterial pressure and arginine vasopressin (AVP) secretion. This study assessed the role of the paraventricular nuclei (PVN) in these actions. Intracerebroventricular ET-1 (10 pmol) or the ET A antagonist BQ-123 (40 nmol) was administered in conscious intact or sinoaortic-denervated (SAD) Long-Evans rats with sham or bilateral electrolytic lesions of the magnocellular region of the PVN. Baseline values did not differ among groups, and artificial cerebrospinal fluid (CSF) induced no significant changes. In sham-lesioned rats, ET-1 increased mean arterial pressure (MAP) 15.9 ± 1.3 mmHg in intact and 22.3 ± 2.7 mmHg in SAD ( P