Objective:To study the effects of epidermal growth factor(EGF)on the coordinated motor behaviors and changes of nigrostriatal dopaminergic system under the impact of EGF in middle-aged rats.Methods:Healthy aged Sprague Dawley(SD)rats were subcutaneously administered EGF(0.1 mg/ml)in the dorsal region for 7 days.Adhe-sive removal test,tapered beam walking test and descending a wire mesh pole test were performed to detect the changes in the coordinated motor behaviors of rats as well as changes in the expression of tyrosine hydroxylase(TH)and dopa-mine transporter(DAT)of nigrostriatal dopaminergic system in rats.Results:Middle-aged rats showed reduced behav-ioral parameters of adhesive removal test,tapered beam walking test and descending a wire mesh pole test compared with those of adult rats(P<0.05),which were improved after treatment with EGF(P<0.05).The expression of TH and DAT in nigrostriatal dopaminergic system was down-regulated in middle-aged rats compared with that in adult rats(P<0.01),however,which were up-regulated after treatment with EGF(P<0.01).Conclusion:EGF can amelio-rate the decline in coordinated motor behaviors and increases the activity of nigrostriatal dopaminergic system in middle-aged rats.

Objective:To study the effects of epidermal growth factor(EGF)on the coordinated motor behaviors and changes of nigrostriatal dopaminergic system under the impact of EGF in middle-aged rats.Methods:Healthy aged Sprague Dawley(SD)rats were subcutaneously administered EGF(0.1 mg/ml)in the dorsal region for 7 days.Adhe-sive removal test,tapered beam walking test and descending a wire mesh pole test were performed to detect the changes in the coordinated motor behaviors of rats as well as changes in the expression of tyrosine hydroxylase(TH)and dopa-mine transporter(DAT)of nigrostriatal dopaminergic system in rats.Results:Middle-aged rats showed reduced behav-ioral parameters of adhesive removal test,tapered beam walking test and descending a wire mesh pole test compared with those of adult rats(P<0.05),which were improved after treatment with EGF(P<0.05).The expression of TH and DAT in nigrostriatal dopaminergic system was down-regulated in middle-aged rats compared with that in adult rats(P<0.01),however,which were up-regulated after treatment with EGF(P<0.01).Conclusion:EGF can amelio-rate the decline in coordinated motor behaviors and increases the activity of nigrostriatal dopaminergic system in middle-aged rats.