Dopamine content in the striatum and expression changes of Bad and Bcl-2 in elderly rats with abnormal behavior.

To determine the dopamine (DA) content in the striatum and the expression changes of the apoptosis-associated proteins Bad and Bcl-2 in the substantia nigra compacta (SNc) in elderly rats with abnormal behavior. Fifty three Sprague-Dawley rats were divided into three groups: adult, age-motorplus (normal behavior) and aged-motorminus (abnormal behavior) using the hanger test. The DA content in the striatum and the expression of tyrosine hydroxylase (TH), Bad and Bcl-2 in the SNc were measured by HPLC/MS (high performance liquid chromatogram-mass spectra) and Western Blot. (1) The results from the hanger test demonstrated that the scores and latency of aged-motorminus group were lower than the age-motorplus group. (2) Results from HPLC-MS showed that, compared with the age-motorplus and adult group, the content of DA in elderly rat striata decreased significantly, with a statistically significant difference. (3) The Western Blot demonstrated that, compared with the adults, the expression of TH in elderly rats significantly decreased, but the difference was not significant between the aged-motorminus group and the age-motorplus group. Compared with the age-motorplus and the adult group, the expression of Bad increased but Bcl-2 decreased in the aged-motorminus group. The decrease in TH content in the SNc correlated with the aging of rats. The decrease in DA content in the striatum may correlate with the abnormal behavior in elderly rats, which could be ascribed to the variations in Bad and Bcl-2.