CALL FOR PAPERS Neurohypophyseal Hormones: From Genomics and Physiology to Disease Oxytocin actions within the supraoptic and paraventricular nuclei: differential effects on peripheral and intranuclear vasopressin release

ema. Oxytocin actions within the supraoptic and paraventricular nuclei: differential effects on peripheral and intranuclear vasopressin release. Am J Physiol Regul Integr Comp Physiol 291: R29–R36, 2006. First published January 19, 2006; doi:10.1152/ajpregu.00763.2005.—In response to forced swimming (FS), AVP is released somato-dendritically within the supraoptic nucleus (SON) and paraventricular nucleus (PVN), but not from neurohypophyseal terminals into blood. Together with AVP, oxytocin (OXT) is released within the SON and PVN. Here, we studied the role of intra-SON and intra-PVN OXT in the regulation of local AVP release and into the blood in male rats. Within the SON, bilateral retrodialysis of an OXT receptor antagonist (OXT-A) in-creased local AVP release in response to FS [60 s, 21°C, vehicle twofold, not significant (ns); OXT-A: 15-fold increase, P 0.05] without significantly affecting basal AVP release. In addition, local OXT-A elevated plasma AVP secretion under basal conditions (two