Objective To investigate the effect of
insulin on c fos and c jun gene
expression in focal ischemic rat brain. Methods
The renovascular hypertensive rats (n=30) were divided at random into 4 groups which received separately with insulin only (Group A,2.1 IU/kg),insulin and glucose (Group B with low dose insulin,2.1 IU/kg;Group C with high dose insulin,4.5 IU/kg)or normal saline(Group D)immediately after middle cerebral artery occlusion (MCAO). Level of c fos mRNA and c jun mRNA on brain sections was measured by in situ hybridization at 3h after MCAO. Results Blood glucose level in group A was 3.80±0.3,3.68±0.3 and 3.69±0.3mmol/L at 1,2 and 3 hours following MCAO,which was lower than in the other groups(P<0.01). In ipsilateral cortex and caudoputamen after MCAO,c fos mRNA significantly increased only in group C(P<0.01) and c fos mRNA greg was 123.58±8.72 and 141.08±8.49. A significant increase in c jun mRNA in ipsilateral cortex was detected in Group A,B and C,and the strongest experssion was seen in Group C(P<0.01). c jun mRNA greg in Group A,B and C was 171.82±7.33、172.56±7.91 and 155.09±7.91. Conclusions These results indicate that the
effect of insulin on c fos and c jun
expression may be one of the mechanisms of neuroprotection of insulin.