[Effect of Baicalin on the expression of connexin 36 in the cerebral cortex and striatum area of Parkinson's disease model rat].

Objective: To investigate the effect of Baicalin on the expression of connexin 36 (Cx36) in cerebral cortex and striatum area of 6-OHDA-induced Parkinson's (PD) model rats and its significance. Methods: Male Sprague-Dawley (SD) rats were randomly divided into 6 groups, 12 in each group: normal control group, PD model group (untreated group), PD model (Medopa group), PD model (Baicalin low dose group) PD model (Baicalin medium dose group) and PD model (Baicalin high dose group). Except for the normal control group, 6-OHDA was injected using microinjection under the mouse brain stereotaxic apparatus to establish the hemiparkinsonian PD model. On the basis of the success of making model, the rats were treated by Medopa and Baicalin (low, medium and high dose). Immunohistochemistry was used to detect tyrosine hydroxylase (TH) and Cx36 expression in cerebral cortex and striatum of the 6 groups. Western-Blot technique was used to detect the cerebral cortex and striatum Cx36 expression changes, and to preliminarily study the effect of Baicalin on rat cerebral cortex and striatum Cx36 expression levels. Results: Immunohistochemical staining and Western blotting showed that the expression of TH-positive neurons and Cx36 in the cerebral cortex and striatum of the PD model group was lower than that of the normal control group (828±188). While expressions of Cx36 in the low, medium and high dose PD model groups of Baicalin (733±118, 759±134, 779±125) were up-regulated, compared with the untreated PD model group (487±125), and the differences were statistically significant (all P <0.05), but the difference between the doses was not statistically significant ( P >0.05). Conclusion: The expression of Cx36 decreases in cerebral cortex and striatum area of 6-OHDA-induced Parkinson's disease model rats, and the expressions of TH and Cx36 in cerebral cortex and striatum increase after treatment with Baicalin, which may provide new drug research direction for Parkinson's disease.