Etude de l'evolution des activites des enzymes mitochondriaux de l'hepatocyte au cours du developpement du rat

Study on the evolution of mitochondrial enzyme activities in hepatocyte during rat development

Some constitutive enzymes of the three isolated fractions of mitochondria outer membrane, inner membrane and matrix, have been investigated in rat hepatocyte during a period varying from the foetal state to the 15th day after birth.

In the three mitochondrial fractions, activities of the studied enzymes present different evolutions. In the matrix, the tricarboxylic enzyme activities have already reached their normal values before birth. In the outer membrane, the NADH-cytochrome c reductase activity increases regularly, in the same way as that of the endoplasmic reticulum NADH-cytochrome c reductase. In the inner membrane, the oxygen consumption is very low before birth, then increases suddenly from the 5th to the 8th day after birth, when it reaches the normal values. The limiting factor of the respiratory chain activities is neither cytochrome oxidase nor the first dehydrogenases.