The relationship between cathepsin L and apoptosis cell in rats after cerebral ischemia reperfusion / 中国医师杂志

ABSTRACT

Objective To investigate the relationship between cathepsin L and apoptosis cell in rats after cerebral ischemia reperfusion.Methods Sixty healthy male Sprague-Dawley Rats (10-12 weeks old,260-300 g) were chosen.Based on the random number table method,the rats were randomly divided into sham-operated control group (Sham group,n =10),ischemia-reperfusion group (model group,n =25),and Z-FY-DMK intervention group (CLI group,n =25).Rats were randomly divided into 6 h,12 h,24 h,and 48 h four subgroups in model group and CLI group,respectively.Modified transient middle cerebral artery occlusion was made as Longa described,the intervention groups were injected intracerebroventricularly Z-FY-DMK (20 μg / 1μ1 ×5 μl) preoperative 30 min prior to surgery,Sham group and schemia reperfusion injury (IRI) group were injected intracerebroventricularly dimethyl sulfoxide (DMSO) 5 μ1 (10ml/L) at the same time.Cell apoptosis was detected by terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) straining.Western blotting was used to detect the expression of cathepsin L and caspase-3.Results In the cortical area of ischemic brain,apoptosis cells of sham operation group were rare,while apoptosis of nerve cells of model group with 6 hours reperfusion were visible,and were gradually increased in the order of 12 hours,24 hours and 48 hours.At the same time point,the apoptosis cells of CL intervention group (6 h,12 h,24 h,48 h) were obviously less than model group (P ＜0.05).Western blotting found little visible cathepsin L protein expression in ischemic cerebral cortex preoptic in the sham group.For model group,the cathepsin L expression initially increased in sub groups with 6 hours reperfusion,reached to a peak in sub groups with 12 hours and 24 hours,and remained a high level in sub groups with 48 hours reperfusion.Compared to model group,the cathepsin L expressions of CL intervention group were obviously decreased at all time points (P ＜ O.05).Conclusions Cathepsin L may be involved in neuronal apoptosis by means of caspases 3 pathway.