Factors in the Metabolism of Galactose.

Abstract

While there are as yet no satisfactory chemical methods available for the rapid determination of galactose in blood, the resistance of this sugar to fermentation by yeast offers a means for the approximate estimation of the amount of this substance present in the blood following its administration. As in the determination of pentoses, previously described, 1 , 2 it has been assumed that the difference between the total non-fermented reduction of the blood and the usual rather constant residual reduction gives a measure of the amount of galactose present.

The details of this series of experiments may be summarized as follows: The sugar (or sugars) in aqueous solution was injected into the marginal ear vein of a fasting, medium sized (about 2 kilos), male rabbit. Blood samples were taken before, and at hourly intervals afterwards. The blood was analyzed for total reduction and reducing power after fermentation. 1 , 2

In view of the facts that the tolerance for glucose is greater after the previous administration of the same sugar, and that glucose has been reported to increase the tolerance for galactose, 3 , 4 these studies have included experiments on the rate of removal of galactose from the blood stream after a previous administration of galactose, and after, or with, the administration of glucose.

The residual reduction of the Idood returned to normal in 2 hours, in 2½ hours and in 3 hours, respectively, after the intravenous injection of 1, 2 and 3 grams of galactose. The previous administration of galactose or glucose, or the simultaneous administration of glucose, has not been found to have any marked effect on the rate of removal of galactose from the blood after its intravenous injection.