title: Effect of dynorphin microinjection in the anterior hypothalamus (AV3V) region on the hemodynamic response to hemorrhage in the rat.
abstract: The region surrounding the anteroventral part of the third ventricle (AV3V) is important for the regulation of cardiovascular homeostasis. In the present study we investigated the effect of the kappa-opioid receptor agonists dynorphin A-(1-17) and dynorphin A-(1-13) microinjected into the AV3V region on mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), stroke volume (SV), and left ventricular stroke work (LVSW) during fixed-volume hemorrhage in conscious rats. During fixed-volume hemorrhage (8 ml/300 g), dynorphin A-(1-17) (6 nmol), microinjected into the AV3V, significantly decreased MAP up to 30 min postinjection (P < 0.05). Recovery of MAP, SV, and LVSW in the dynorphin A-(1-17) group following hemorrhage was found to be significantly attenuated compared to that in animals receiving microinjection of normal saline (NS) vehicle into the AV3V (P < 0.05). Hypothalamic microinjection of dynorphin A-(1-13) (6 nmol) also attenuated the recovery of SV following hemorrhage compared with the NS group (P < 0.05). No significant effects were observed on HR or CO following microinjection of dynorphin into the AV3V region. The results of this study suggest that activation of the kappa-opiate receptor system in the AV3V region of the hypothalamus can attenuate the compensatory cardiovascular responses to hemorrhage.
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia 19104.
authors.forename: L
authors.initials: L
authors.lastname: Fan
authors.forename: N S
authors.initials: NS
authors.lastname: Yeston
authors.forename: T K
authors.initials: TK
authors.lastname: McIntosh
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004399:Dynorphins / Q000008:administration & dosage / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006470:Hemorrhage / Q000503:physiopathology*; D007031:Hypothalamus / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008845:Microinjections; D051381:Rats; D017207:Rats, Sprague-Dawley; D013318:Stroke Volume / Q000187:drug effects
chemical_list: D004399:Dynorphins