ABSTRACT
Aim To investigate the changes of cerebral blood flow in rats with diabetic cognitive impairment by two-channel laser Doppler flowmeter,and to explore the changes of cerebral blood flow in diabetic rats with cognitive impairment and to investigate the changes of cerebral blood flow lesions and the central nervous system function changes in the study to provide pre-foundation.Methods Thirty-four male Wistar rats were randomly divided into two groups:blank control group and diabetic model group.The rats in the model group were treated with streptozotocin (STZ) 60 mg · kg-1,and the glucose oxidase method was used to determine fasting blood glucose ≥ 16.7 mmol · L-1 as the standard of the model.The Water maze was used to observe the behavioral changes of diabetic rats.Dual-channel laser doppler flowmeter was used to measure cerebral blood flow in diabetic rats with cognitive impairment.Another 34 male Wistar rats were randomly divided into two groups:control group and diabetic model group.Dual-channel laser doppler flowmeter was used to dynamically monitor cerebral blood flow on 0 d,7 d,14 d,21 d,28 d,35 d,42 d,56 d and 75 d.ELISA was applied to detect the concentration of iNOS,eNOS and ET-1 in cerebrospinal fluid.Results Morris water maze test showed that the time of the platform (latency) was significantly longer than that of the blank control group(P ＜0.05).The cerebral blood flow/100 g of diabetic rats with cognitive impairment was significantly lower than that of the control group (P ＜ O.05),and the blood flow in the model group was significantly lower than that in the model group (P ＜ 0.05).Compared with control group,iNOS and eNOS concentrations were markedly elevated,while ET-1 concentration obviously decreased.Conclusions The decrease of blood flow in the frontal cortex of diabetic rats with cognitive impairment suggests that it may be one of the factors leading to cognitive impairment in diabetes mellitus.Cerebral blood flow reduction occurs in the early stages of diabetes,followed by no significant deterioration.Cerebral blood flow may not be related to the changes of NO and ET-1,but the trend of cerebral blood flow may be related to the change of the two.