title: The effect of prostaglandin E1 on brainstem blood flow disturbance in an animal model of vertebrobasilar insufficiency.
abstract: Using an animal model of vertebrobasilar insufficiency (VBI), in which brainstem circulatory disturbance was induced in rats, we examined how prostaglandin E1 (PG-E1) affects brainstem blood flow (BBF) to clarify whether it is effective against VBI. Fifteen healthy male Wister rats that displayed positive responses to Preyer's reflex were used. Their BBF was continuously measured on the left side of the midline of the brainstem using laser Doppler flowmetry. A rat model of VBI, a pathological condition that presents with decreased BBF, was prepared by applying a vertebral artery clamp ipsilateral to the BBF measuring site and inducing hypotension of 60-70 mmHg by blood withdrawal. Saline as a control (n = 5), 5 ng/kg/min (n = 5) or 10 ng/kg/min (n = 5) PG-E1 at a dose was continuously administered to the rats using a motor-driven syringe pump. The effects of the drugs on the rats' BBF were evaluated. BBF, which was decreased by the unilateral vertebral artery clamping combined with blood withdrawal-induced hypotension, recovered in a dose-dependent manner after the administration of 5 or 10 ng/kg/min PG-E1, and complete recovery to the baseline level was achieved by 60 min treatment; however, no such effect was observed for intravenous saline. These results suggest that PG-E1 acts on local vessels and improves blood flow insufficiency in the brainstem in our animal model of VBI. PG-E1 might be useful as a cerebral vasodilator for VBI.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Nara Medical University School of Medicine, 840 Shijo, Kashihara, Nara, 634-8522, Japan, toshya@naramed-u.ac.jp.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Yamanaka
authors.forename: Takayuki
authors.initials: T
authors.lastname: Murai
authors.forename: Yachiyo
authors.initials: Y
authors.lastname: Sawai
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Okamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hosoi
mesh_terms: D000527:Alprostadil / Q000494:pharmacology*; D000818:Animals; D001933:Brain Stem / Q000098:blood supply*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007262:Infusions, Intravenous; D017078:Laser-Doppler Flowmetry; D008297:Male; D051381:Rats; D012039:Regional Blood Flow / Q000187:drug effects; D014715:Vertebrobasilar Insufficiency / Q000503:physiopathology*
chemical_list: D000527:Alprostadil