关键词: PPARγ; 血脑屏障; 基质金属蛋白酶类; 再灌注损伤; 吡咯列酮

Abstract: Objective To investigate the protective effects of peroxisome proliferator-activated receptor gamma (PPARγ) agonist on the blood brain barrier (BBB) of the experimental ischemics brain tissue. Furthermore , to analyze its probable mechanism combining with its effect on the expressionof the MM P-9 mRNA. Methods Adult male SD rats were divided into four groups: sham-operation+normal saline (NS), ischemia-reperfusion ( I/R) +NS, I/R+ low-dose Pioglitazone (PGZ, PPARγ agonists, 10 mg/kg,once daily), and I/R+high-dose PGZ (15 mg/kg, once daily).The mode of transient middle cerebral artery occulision was made by using the suture of Longa. By intragastric administration ,all the rats were given PGZ daily for 3 days before operation, the low-dose group with 10mg&#8226;kg-1&#8226;d-1 and the high-dose group with 15mg&#8226;kg-1&#8226;d-1. The content of Evans Blue (EB) and the expression of MMP-9 mRNA were measured by Spectrophotometry and RT-PCR at 24 hrs after ischemia.Results The content of EB of the low-dose PGZ group (0.062±0.014A/g) and the high-dose PGZ group (0.043±0.011A/g) were significantly reduced compared with that of the I/R+NS group (0.081±0.015A/g) (P <0. 05), with significance difference during any two groups; the expression of MMP-9mRNA of the low-dose PGZ group (0.268±0.021) and the high-dose PGZ group (0.194±0.017) were significantly reduced compared with that of the I/R+NS group (0.371±0.019) (P <0. 05),but no significance difference between low-dose PGZ and high-dose PGZ groups.Conclusion PPARγagonists can improve the permeation of blood brain barrie in the ischemia brain tissue by down-regulate the expression of MMP-9mRNA, and it may be one of the mechanisms in the protective action of PPARγ on ischemia-reperfusion injury.

Key words: PPAR gamma; Blood- brain barrie; Matrix metalloproteinases; Reperfusion injury; Brain ischemia; Pioglitazone