Effect of cortisone, thyroxine and cold on femurs of guinea pigs

¹ Laboratory for Research on the Biochemistry of Aging, Department of Experimental Medicine, Saint Joseph Hospital, Burbank, California

The femurs of guinea pigs were analyzed for total mineral, collagen and hexosamine contents following daily administration of 25 µg of l-thyroxine and/or 60 mg/kg of cortisone acetate for 30 days. As judged from values predicted from femur length, cortisone markedly inhibited growth; mineral and hexosamine contents were consistent with growth, and collagen content was greater than predicted. Thyroxine did not reduce growth of femurs but caused less of its constituents to be deposited. Animals exposed to 2°–4°C for 90 days demonstrated a growth pattern and femur composition similar to that observed in thyroxine-treated animals. When cold-exposed animals were returned to room temperature and permitted to attain the weight of the unexposed controls, even though femur length was as great or greater, mineral, collagen and hexosamine contents were below the predicted values.