ABSTRACT
AIM: To assess an effect of ovariectomy (OE) on the cerebral blood flow, endothelium-dependent vasodilation, neurological, cognitive and locomotor deficit as markers of brain damage after focal ischemia in rats. MATERIAL AND METHODS: The study was conducted in 48 female Wistar rats. Ovariectomy was performed with ovaries and uterine body extirpation, cerebral ischemia was performed by middle cerebral artery occlusion (MCAO) in rats. To assess brain damage, Combs and Garcia scores, 'open field' test (OFT), 'extrapolatory escape test' (EET), 'passive avoidance test' (PAT), 'beam-walking test' were used. Cerebral blood flow was measured using ultrasonic flowmetry. RESULTS AND CONCLUSION: After 7 days of MCAO, the cerebral blood flow in ovarioectomized animals was reduced by 20% compared to sham-ovariectomized animals. Ovariectomized animals with MCAO showed a three-fold endothelium-dependent vasodilation reduction (the reaction of cerebral vessels to the introduction of acetylcholine and N-L-arginine), indicating the presence of severe endothelial dysfunction. In ovarioectomized animals, the cerebral blood flow was reduced by 34% compared to sham-operated animals. MCAO and OE taken together resulted in more than 2-fold increase in neurological, motor disturbances, 3-fold decrease in motor activity of the animals in the OP test. Focal ischemia in ovarioectomized animals with endothelial dysfunction led to memory decrease by 1/5 fold in PAT and by 2-fold in EET.
Subject(s)
Brain Ischemia , Cerebrovascular Circulation , Estrogens , Infarction, Middle Cerebral Artery , Animals , Estrogens/deficiency , Female , Ovariectomy , Rats , Rats, WistarABSTRACT
Dose-dependent cerebroprotective effect of magnesium hydroxybutyrate (MHB) on common carotid artery occlusion model in rats was established. Administration of 150 mg/kg MHB led to significant decrease in animal mortality (up to 9.3 times) in comparison to control (p < 0.05). This MHB dose also produced significant decrease of neurological deficit on the McGraw scale in comparison to control and magnesium sulfate (50% and 20%, respectively). The MHB treated animals also showed improved locomotor and exploratory performance in the open-field test and retained memory performance in the passive avoidance test and extrapolation escape task test. The administration of 150 mg/kg MHB produced three-fold (p < 0.05) decrease of brain edema in animals with cerebral blood flow impairment in comparison to animals treated with magnesium sulfate and cavinton.
