Effects of Gonad Stimulating Extracts on Basal Gaseous Metabolism in Rats.

Reiss and Winter, 1 using extracts containing the sex maturity stimulating principle from the urine of pregnant women, found no constant effects on the oxygen consumption, carbon dioxide production or respiratory quotient in rabbits. They used anesthetized animals, however, gave enormous doses, 200 to 4000 units of the material subcutaneously and followed the metabolism for only a few hours after each injection. We have used what are presumably more physiological doses, without anesthesia, and have followed the metabolic level during and after periods of continued daily administration.

Two sources of the sex maturity or gonad stimulating principle were used. One was an extract of sheep anterior lobe∗ and the other we prepared from the urine of women in the first half of pregnancy after the method of Biedl. 2 The potency of the extracts used was assayed by testing on infantile rats. Twelve rats were used, 9 females and 3 males. Twenty determinations made in the first 1 to 4 hours following the subcutaneous administration of the extracts in doses of 2 to 8 units showed no significant changes in the metabolic rates, although the tendency was towards an increase. No effects on the respiratory quotient were found.

These same rats were given doses of 1 to 6 rat units per day for periods of 8 to 24 days. Frequent metabolism determinations made during and after the periods of treatment showed no significant changes from the preliminary average level. The total average of the metabolic rates during the period of administration of the extracts was only 2% higher than the normal average rate. These results would indicate that in rats this material is without any general metabolic effect.