Abstract
Rapid disappearance of body carbohydrate and correspondingly high rates of carbohydrate oxidation were observed in fasted hypophysectomized rats, and anterior pituitary extracts were found to restore to these animals the ability to maintain their carbohydrate levels. 1 , 2 , 3 In order to determine whether hypophysectomized rats differed from the normal in their carbohydrate metabolism in the fed state as well as when fasted, and to determine whether anterior lobe extracts acted also under these conditions, the following experiments were performed:
Normal and hypophysectomized rats were fasted, then fed known amounts of glucose. The oxygen consumption, respiratory quotients and N excretion were determined during the next 4 hours. Then the animals were killed and the levels of blood glucose and of liver and muscle glycogen were determined, as were also the amounts of glucose remaining in the alimentary tracts. Identical experiments were performed at the same time on both normal and hypophysectomized rats which had been treated for various lengths of time with standard alkaline extracts of anterior pituitary. Respiratory data and carbohydrate levels were also determined in normal unfed rats, with and without A. P. injections.
It was found in the hypophysectomized rats that 74% of the absorbed glucose was oxidized, as compared to 53% in the normal animals. The hypophysectomized rats stored less carbohydrate than did the normal rats, the difference being accounted for approximately by the increase in the proportion of carbohydrate oxidized. The actual amounts of carbohydrate apparently oxidized were about the same in the 2 series, in spite of the fact that the total oxygen consumption, and the rate of absorption of the fed glucose were much smaller in the hypophysectomized rats. Therefore, as also found previously by others, 4 the proportion of total calories obtained from carbohydrate was higher in the operated animals.
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