title: Galanin as a physiological neurotransmitter in hemodynamic control of arginine vasopressin release in rats.
abstract: Previous neuroanatomical studies have revealed a localization of galanin in several nuclei in the brain stem which are involved in the hemodynamic control of arginine vasopressin (AVP) release. The present study, therefore, investigates the contribution of endogenous galanin to the plasma volume-mediated control of AVP release in conscious rats. Injection of synthetic rat galanin (12.5-50 pmol/rat) into the cisterna magna (i.c.s.) suppressed plasma AVP increased by polyethylene glycol-induced hypovolemia (2.45 +/- 0.24 pg/ml at 50 pmol/rat vs. the vehicle group 5.72 +/- 0.69 pg/ml, p < 0.01). In contrast, when plasma AVP was suppressed by isotonic plasma volume expansion, immunoneutralization of endogenous galanin by antigalanin-antibody i.c.s. significantly reversed the suppression (1.02 +/- 0.07 pg/ml vs. vehicle group 0.63 +/- 0.05 pg/ml, p < 0.01) without altering the mean arterial blood pressure. These results suggest that endogenous galanin is physiologically involved in the plasma volume-mediated control of AVP release through an inhibitory action on this pathway.
authors.affiliation: First Department of Internal Medicine, Nagoya University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kondo
authors.forename: T
authors.initials: T
authors.lastname: Murase
authors.forename: K
authors.initials: K
authors.lastname: Otake
authors.forename: M
authors.initials: M
authors.lastname: Ito
authors.forename: F
authors.initials: F
authors.lastname: Kurimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Oiso
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin / Q000097:blood / Q000378:metabolism*; D001810:Blood Volume; D019004:Galanin; D006439:Hemodynamics / Q000502:physiology*; D007116:Immunization, Passive; D007276:Injections, Intraventricular; D008297:Male; D018377:Neurotransmitter Agents / Q000502:physiology*; D009994:Osmolar Concentration; D010455:Peptides / Q000276:immunology / Q000494:pharmacology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018377:Neurotransmitter Agents; D010455:Peptides; D001127:Arginine Vasopressin; D019004:Galanin