Synthesis of rapidly‐labelled brain RNA in the rat during stagnant hypoxia in the course of ontogeny

Abstract

SIRAKOVA, I. A., SIRAKOV, L. M., J~L E K , L., and RYCHL~K, I. (19138). Synthesis of Rapidly-lnbelled Brain R N A in the R a t During StagizantHypoxia in the Course of Ontogeny. DEVELOPMENTAL PsucilosroLocu, I(3): 189-195. T h e nucleic acids of the cytoplasmic and nuclear fraction of the brain honiogenate were isolated by phenol procedure then were fractionated on a linear sucrose density gradient. T h e in vivo incorporation of [3H]-uridine into different types of RNA and the template activity of these nucleic acid fractions in control and hypoxic animals were studied in vitro in a cell-free protein synthetic system of E. coli. In adult animals, as in 25-day-old rats, stagnant hypoxia decreases the total synthesis of rapidly-labelled RNA in nuclei and impairs the template activity in cytoplasm. In 12-day-old rats, the synthesis of rapidly-labelled RNA does not change in stagnant hypoxia and the template activity increases mainly in the low molecular weight fractions. Metabolic adaptation of immature nervous tissue to hypoxia involves specific changes of protein and nucleic acid metabolism as well as in carbohydrate and energy metabolism.