Chemotherapeutic Investigations of Cyanine Dyes

Abstract

Yellow and black agouti segregates were obtained by crossing yellow o o with albino 9 9 . The yellow and black littermates of the same sex differed in the one chromosome or part thereof which carried the "yellow" gene. Sets of unmated yellow and black littermates were compated within each sex and growth period. The mice were self-fed in individual cages. The only food was a complete ground ration. Food loss was prevented and excretions were recovered. Live wt. gains, food consumption, and feces production were obtained by 10-day periods from 30 to 50 days and then by 20-day periods. Each mouse was chloroformed and its body analyzed for fat, N, water and total dry matter. Body composition was also obtained for yellow and black mice from 2 litters within each sex at 25 days of age. From 25 to 35 or 40 days of age, yellow and black mice of the same sex were nearly alike in gain and food consumption, and the gain was chiefly protein. After 40 days, yellow mice of both sexes exceeded the black littermates greatly in gains but moderately in food consumption. The extra gain of the yellow mice was entirely fat tissue. The "yellow" gene greatly increases the energy stored per gm. of gain but sharply reduces the food required per gm. The yellow gene accomplished increased fat deposition and lowered food requirements per unit of gain by increasing the appetite and reducing the energy expended in body work, beginning at 35 or 40 days of age. The percentage of food calories eliminated in feces was about 19 in the 25- to 30-day period to about 23 in the 25- to 300-day period. It was slightly lower for black [female] [female]. The increase in nutrients absorbed by yellow, as compared with black mice, was nearly in proportion to the increase in food consumption. The increase in energy for body work by the yellow mice was proportionally much less than the increase in their avg. body wt., particularly in [female] [female]. The data emphasize how little of the food energy is stored compared with that used for maintenance and activity. Energy stored as fat and protein represented 2-11% of the total food energy during the several periods from 25 to 300 days of age, whereas energy for body work represented 70-80%. Of the total calories consumed, the yellow mice stored 2-5% more than the black littermates and used at least that much less for maintenance and activity. A small reduction in maintenance food caused a large increase in food stored. There is evidence that the action of the yellow gene is similar to that of the genes affecting fat deposition in animals generally.