Abstract
The enzyme activity of hepatic mitochondria from Meishan was compared with those of Landrace, Large White and Duroc of 90kg in weight. Although there were no significant breed differences in succinate-cytochrome c reductase (complexes II and III), cytochrome c oxidase (complex IV) and NADH oxidase, which measures the entire respiratory chain from NADH to O2, Meishan showed the activity of NADH-ferricyanide reductase (complex I) to be 17-24% less than that in the other breeds. Meishan required a longer time period to reach a weight of 90kg than the other breeds, but changes in NADH-ferricyanide reductase with ageing were not observed. Since seven subunits of complex I were encoded by mitochondrial DNA and Meishan and European breeds have different restriction enzyme cleavage patterns of mitochondrial DNA, the differences in the activities of Meishan and other breeds may possibly be associated with variation in mitochondrial DNA. The inheritance mode of NADH-ferricyanide reductase activity is now being investigated.
