Age-dependent changes of biochemical parameters during the perfusion of the isolated rat liver

The livers were isolated from Sprague-Dawley rats in 5 groups aged from 4 to 5, 10 to 12, 24 to 26, 30 to 32 and 35 to 37 months and perfused for 5 h to study the activities of GOT and GPT, the K+ level and to form the quotient of lactate/pyruvate and beta-hydroxybutyrate/acetoacetate in the perfusion medium. The K+ level showed no age related changes, which eliminates, by use of the method described in this paper, the K+ level as sensitive parameter of cell membrane function. Both redox quotients indicate a metabolic breakdown after 240 min perfusion in the oldest group, which points to a reduced adaptability in senescent animals to changed metabolical conditions during the perfusion of the isolated livers. The transaminases GOT and GPT proved to be the most sensitive parameters of cell membrane function, allowing the finest discriminations between the various age groups. Here also the senescent group showed the first signs of membrane damages.