Blood Sugar in Rats Rendered Cataractous by Dietary Procedures

Abstract

Young growing rats were given adequate diets containing various carbohydrates as 60% of the diet. Blood sugar was determined by the Folin micro method. Seventeen out of eighteen rats receiving lactose developed cataract at an average time of 44 days. The three rats receiving galactose exhibited cataract on the eleventh day. Glucose, sucrose and starch did not cause cataract. The mean blood sugar level in rats receiving glucose ad libitum was 121 mg. per 100 cc. The level in rats receiving starch was essentially the same, but was slightly higher in rats receiving sucrose. Lactose and galactose caused high and extremely variable blood sugar levels. The mean of eighty-nine determinations upon lactose rats was 160 mg.; the highest value found was 234 mg. The mean of twenty-seven determinations upon galactose rats was 372 mg.; the highest level recorded was 556 mg. Considered statistically, the chances are more than 1,000,000,000 to 1 that these mean values are significantly greater than the corresponding mean value for rats receiving glucose. It may be significant that the sugar that caused cataract in the shorter period (galactose) also produced the highest blood sugar levels. Cataract was produced in young growing rats by a diet deficient in vitamin G. The mean of blood sugar determinations upon such rats was somewhat lower than the mean blood sugar of normal controls. The cataract produced by lactose or galactose feeding was easily distinguished with the ophthalmoscope from cataract resulting from vitamin deficiency.