Expression of SIRT3 in kidneys of rats on diets with different calories

Objective To study the expression of SIRT3 in kidneys of rats on diets with different calories. Methods Renal tissue was taken from 344 healthy male Fisher rats at the age of 12 months that had free access to high calorie (HC) diets with their calorie restricted. Expressions of SIRT3 and p16INK4A were detected by immunohistochemistry and Western blot, respectively, with agingassociated β-galactosidase (SA-β-gal) staining. Results The activity of β-galactosidase and the expression of p16INK4A in renal tissue of rats increased with the increased calorie of diets(P<0.05). Western blot showed that the expression of SIRT3 protein in renal tissue of rats decreased with the increased calorie of diets. Immunohistochemistry showed that the SIRT3 protein was mainly expressed in renal tubules and weakly expressed in glomeruli, which increased with the increased calorie of diets (P<0.05) and was consistent with that detected by Western blot. Conclusion Calorie restriction can delay the aging of rat kidneys. Expression of SIRT3 may be closely related with the aging of rat kidneys caused by HC.