Insulin Stimulates the Incorporation of32Piinto Ribonucleic Acid in Cultured Sertoli Cells*

Chronic treatment of cultured Sertoli cells with insulin, FSH, or testosterone does not affect the number of attached cells or the amount of total RNA or poly(A)+ RNA per culture dish. However, Sertoli cells cultured in the presence of insulin have a nearly 2-fold stimulated incorporation of 32Pi into poly(A)+ RNA. The other hormone treatments did not induce any stimulation over control values. The t1/2 of the total poly(A)+ RNA was determined in pulse-chase experiments. None of the hormone treatments affected the t1/2 (16 h) of the total poly(A)+ RNA. The incorporation of [3H]uridine and 32Pi into the total nucleotide pools and into some individual nucleotides was determined by high pressure liquid chromatography analysis of acid-soluble extracts. Insulin-treated cells had approximately a 1.5-fold increased specific activity of [3H]uridine or 32Pi into the total nucleotide pool and in ATP, GTP, and UTP pools. Insulin apparently stimulates the uptake of phosphorylation (or both) of free nucleosides.