Hepatic Sirt3 expression declines postpartum in dairy goats

The experiments reported in this research communication aimed to plot the expression pattern of Sirt3, a master regulator of energy metabolism and antioxidation defence, in the liver of dairy goats during perinatal period. Ten healthy dairy goats in late pregnancy were chosen, and needle biopsy was applied to collect liver samples at 1-week intervals. Protein levels of hepatic Sirt3 were analysed by western-blotting. Serum enzyme activities of manganese superoxide dismutase (Mn-SOD) and non-esterified fatty acids (NEFA) levels were measured, and their correlation with Sirt3 mRNA levels was also estimated. Compared with >3-week before parturition (BP), Sirt3 proteins were significantly reduced at 1-week after parturition (AP) and 2-week AP (P < 0·05), but increased on the day of parturition (P < 0·01). Correlation analysis revealed a positive association between hepatic Sirt3 mRNA levels and serum enzyme activity of Mn-SOD (r = 0·46), but a negative association between that and serum NEFA levels (r = -0·41). These data indicate that the decreased hepatic expression of Sirt3 might be one of the reasons that dairy goats undergo oxidative stress after parturition.