PHOSPHORUS METABOLISM OF THE ADRENAL GLAND: EFFECT OF COLD STRESS ON THE LABELING OF PHOSPHOLIPID AND RNA NUCLEOTIDES WITH RADIOACTIVE INORGANIC PHOSPHATE1

Abstract

The specific activity of the inorganic P of the adrenal gland of rats maintained in a cold environment (3 [plus or minus] 1[degree] C) for 16 hours following the injection of inorganic P32 was greater than that of similar animals maintained at room temperature. The specific activity of both the lipid P and the ribonucleic acid (RNA) nucleo-tide P also increased, as did the specific activity of each of these fractions relative to that of the inorganic P of either the plasma or the adrenal gland itself. Changes in the P metabolism of the adrenal gland during a short exposure to a cold environment are apparently brought about by the liberation of ACTH from the pituitary. They include an increase in the rate at which inorganic p32 passes from the extracellular to the cellular portion of the gland and a net synthesis of P-containing organic compounds (e.g. lipid P, RNA nucleotides.).