EFFECT OF SEX HORMONES ON THE METABOLISM OF COLLAGEN AND 45CA BY THE BONES OF YOUNG GONADECTOMIZED RATS

Abstract

ABSTRACT Collagen and calcium metabolism in long bones of young gonadectomized rats was studied using a double radioisotope labelling method. Rats were treated, or not, for 20 days with testosterone propionate (TP) or oestrone (Oe). 14C-proline was used in the labelling of bone collagen and the conversion of proline to hydroxyproline was taken as an index of collagen synthesis. The content and specific activity of hydroxyproline in serum and urine were also determined. 45Ca was used in the labelling of bone calcium and the changes in 45Ca content in the bone were used as a measure of mineral accretion in the skeleton. Serum and urine were also studied for calcium content and specific activity. The overall results suggest that both sex hormones used had significant anabolizing action on bone collagen and calcium. These hormones enhanced the synthesis and breakdown of collagen and the deposition of calcium in the bones. The action of TP was much more marked than the action of Oe under the conditions of the present experiment.