Comparative studies on mitochondrial respiration in four strains of rats (Rattus norvegicus)

Mitochondrial respiration and ATP synthesis were examined in young rats of the Sprague-Dawley, Wistar, BHE and Zucker strains. Both lean and obese Zucker rats were studied. Pyruvate-supported state 3 respiration was highest in mitochondria from Sprague-Dawley rats and least in mitochondria from obese Zucker rats. Succinate-supported state 3 respiration was highest in the Wistar group and least in the Sprague-Dawley rats. There appeared to be no relationship between oxygen consumption and the genetic tendency for hepatic hyperlipogenesis. ATP synthesis was greatest in the obese Zucker rats and least in the Sprague-Dawley rats. Differences in liver weights and mitochondrial yields may explain, in part, these observed strain differences in mitochondrial activity.