Central NOS inhibition differentially affects vasopressin gene expression in hypothalamic nuclei in septic rats

Abstract

Our aim was to investigate the effect of central NOS inhibition on hypothalamic arginine vasopressin (AVP) gene expression, hormone release and on the cardiovascular response during experimental sepsis. Male Wistar rats were intracerebroventricularly injected with the non-selective NO synthase (NOS) inhibitor (L-NAME) or aminoguanidine, a selective inhibitor of the inducible isoform (iNOS). After 30min, sepsis was induced by cecal ligation and puncture (CLP) causing an increase in heart rate (HR), as well as a reduction in median arterial pressure (MAP) and AVP expression ratio (AVPR), mainly in the supraoptic nucleus. AVP plasma levels (AVPp) increased in the early but not in the late phase..