Lactate and pyruvate increase the incorporation of [3H]proline into collagen [3H]hydroxyproline in liver slices of CCl4 cirrhotic rats

Lactate and pyruvate enhanced the incorporation of [3H]proline into collagen [3H]hydroxyproline when added to liver slices of CCl4-treated rats. In addition, pyruvate stimulated the accumulation of cAMP, reaching maximum values after 10 minutes of incubation. Similar results were obtained with newborn rat calvariae, a tissue that normally produces large amounts of type I collagen. In normal liver, which produces relatively small amounts of collagen, lactate had no effect on cAMP levels or collagen synthesis. Pyruvate stimulated the accumulation of cAMP, but had no effect on collagen synthesis. These results indicate that different control mechanisms are involved in regulation of collagen biosynthesis in normal as compared with cirrhotic liver; the latter resembling mesenchymal tissues specialized in collagen production such as newborn rat calvariae.