title: Plasma arginine-vasopressin following experimental stroke: effect of osmotherapy.
abstract: Neurohumoral responses have been implicated in the pathogenesis of ischemia-evoked cerebral edema. In a well-characterized animal model of ischemic stroke, the present study was undertaken to 1) study the profile of plasma arginine-vasopressin (AVP), and 2) determine whether osmotherapy with mannitol and various concentrations of hypertonic saline (HS) solutions influence plasma AVP levels. Halothane-anesthetized adult male Wistar rats were subjected to 2 h of middle cerebral artery occlusion with the intraluminal filament technique. Plasma AVP levels (means +/- SD) were significantly elevated at 24 h (42 +/- 21 pg/ml), 48 h (50 +/- 28 pg/ml), and 72 h (110 +/- 47 pg/ml), and returned to baseline at 96 h (22 +/- 15 pg/ml) following middle cerebral artery occlusion compared with sham-operated controls (14 +/- 7 pg/ml). Plasma AVP levels at 72 h were significantly attenuated with 7.5% HS (37 +/- 8 pg/ml; 360 +/- 11 osmol/l) compared with 0.9% saline (73 +/- 6; 292 +/- 6 osmol/l), 3% HS (66 +/- 8 pg/ml; 303 +/- 12 osmol/l), or mannitol (74 +/- 9 pg/ml; 313 +/- 14 osmol/l) treatment. HS (7.5%) significantly attenuated water content in the ipsilateral and contralateral hemispheres compared with surgical shams, 0.9% saline, 3% HS, and mannitol treatments. Peak plasma AVP levels were not associated with direct histopathological injury to the anterior hypothalamus. Attenuation of brain water content with 7.5% HS treatment coincides with attenuated serum AVP levels, and we speculate that this may represent one additional mechanism by which osmotherapy attenuates edema associated with ischemic stroke.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Chang
authors.forename: Tsung-Ying
authors.initials: TY
authors.lastname: Chen
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Chen
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Crain
authors.forename: Thomas J K
authors.initials: TJ
authors.lastname: Toung
authors.forename: Anish
authors.initials: A
authors.lastname: Bhardwaj
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin / Q000097:blood*; D001929:Brain Edema / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D004305:Dose-Response Relationship, Drug; D020244:Infarction, Middle Cerebral Artery / Q000150:complications; D002546:Ischemic Attack, Transient / Q000097:blood / Q000150:complications / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008353:Mannitol / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D012462:Saline Solution, Hypertonic / Q000627:therapeutic use*; D020521:Stroke / Q000097:blood* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D013318:Stroke Volume / Q000502:physiology
chemical_list: D012462:Saline Solution, Hypertonic; D001127:Arginine Vasopressin; D008353:Mannitol