EFFECT OF GROWTH HORMONE ON MUSCLE AND SKIN COLLAGEN IN NEONATAL THYROIDECTOMIZED RATS

Abstract

The wt. gain of skeletal muscle was more severely retarded than that of the total body in rats thyroidectomized at birth or at weaning. There was no effect in muscle on the water, total protein, and collagen percentages. Growth hormone admn. for 100 days to rats thyroidectomized at birth produced a 2-fold increase in the muscle collagen content (% wet wt. or % total protein) and a 4-fold increase in body wt. but had no effect on the subnormal muscle-body wt. ratio or total protein and water percentages in muscle. There was also marked thickening of the skin (corium), an increase in the size of hair shafts, and an increase in collagen and total protein percentages of skin in growth hormone treated rats.