[Characteristics of the action of dexamethasone and hydrocortisone on the biosynthesis of mitochondrial and cytoplasmic RNA in the rat liver].

In experiments on intact rats it was established that dexamethasone and hydrocortisone induce biosynthesis of mitochondrial RNA in a similar way, the, action being of the phase character. Three maxima of RNA biosynthesis induction in the liver mitochondria were found. The first increase of RNA biosynthesis intensity in organelles was noted 15 minutes after administration of glucocorticoids, it was short-term and less pronounced than the subsequent ones. The maximal increase of mitochondrial RNA synthesis was observed at the 4th hour of the action of glucocorticoids (the 3rd phase). The increase of mitochondrial RNA synthesis intensity was associated with the decrease of the specific radioactivity of cytoplasmic RNA.