title: Vasopressin and sympathetic system mediate the cardiovascular effects of the angiotensin II in the bed nucleus of the stria terminalis in rat.
abstract: The bed nucleus of the stria terminalis (BST) is involved in cardiovascular regulation. The angiotensin II (Ang II) receptor (AT1), and angiotensinogen were found in the BST. In our previous study we found that microinjection of Ang II into the BST produced a pressor response. This study was performed to find the mechanisms mediating this response in anesthetized rats. Ang II was microinjected into the BST and the cardiovascular responses were re-tested after systemic injection of a blocker of autonomic or vasopressin V1 receptor. The ganglionic nicotinic receptor blocker, hexamethonium dichloride, attenuated the pressor response to Ang II, indicating that the cardiovascular sympathetic system is involved in the pressor effect of Ang II. A selective vasopressin V1 receptor antagonist greatly attenuated the pressor effect of Ang II, indicating that the Ang II increases the arterial pressure via stimulation of vasopressin release as well. In conclusion, in the BST, Ang II as a neurotransmitter increases blood pressure by exciting cardiovascular sympathetic system and directly or indirectly causing vasopressin to release into bloodstream by VPN. This is an interesting new finding that not only circulating Ang II but also brain Ang II makes vasopressin release.
authors.affiliation: Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Nasimi
authors.affiliation: Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. Electronic address: kafami.m@gmail.com.
authors.forename: Marzieh
authors.initials: M
authors.lastname: Kafami
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D065092:Antidiuretic Hormone Receptor Antagonists / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D005725:Ganglia, Autonomic / Q000378:metabolism; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D008845:Microinjections; D010275:Parasympathetic Nervous System / Q000378:metabolism; D017208:Rats, Wistar; D017483:Receptors, Vasopressin / Q000378:metabolism; D012686:Septal Nuclei / Q000187:drug effects* / Q000502:physiology; D014667:Vasopressins / Q000494:pharmacology*
chemical_list: D065092:Antidiuretic Hormone Receptor Antagonists; D017483:Receptors, Vasopressin; D014667:Vasopressins; D000804:Angiotensin II
keywords: Angiotensin II; Arterial pressure; Atropine; Bed nucleus of the stria terminalis; Hexamethonium; Vasopressin