[Effect of dl-3-N-butylphthalide on the expression of hsp70 mRNA and c-fos in transient cerebral ischemic and reperfused rat brain].

Transient cerebral ischemia may cause striking changes in gene expression in rat brain. The induction of heat shock protein 70 (hsp70) mRNA is considered to be an important marker of cerebral ischemia injury, and c-fos may upregulate the expression of other genes related to the secondary injuries. dl-3-n-Butylphthaline(NBP) had been shown to have good anti-cerebral ischemic effect. Using the in situ hybridization and Northern blot technique, the effect of NBP on the expression of hsp70 mRNA and c-fos in transient middle cerebral artery occlusion (MCAo) rat caused by intraluminal thread was studied, and found that the expression of hsp70 mRNA was at the lesioned site at 1 h of reperfusion. It increased gradually with the duration of reperfusion time and peaked at 12 h at the lesioned site. With NBP treatment(i.p. 10 mg.kg-1 10 min before ischemia or 20 mg.kg-1 after ischemia), the expression of hsp70 mRNA attenuated significantly. For c-fos, the expression appeared at 0.5 h of reperfusion, peaked at 3 h, and decreased at 6 h. NBP pretreatment (10 mg.kg-1 10 min before ischemia) also decreased the c-fos expression. The same results were obtained with Northern blot technique. Since NBP had been shown to have good anti-cerebral ischemic effects, the attenuating effect on gene expression seemed to be the secondary effect after the alleviation of tissue injury.