The effect of fasting and of vitamin B deprivation on the chemical composition of rats'blood

Abstract

The recent publication of data on the blood of pigeons in polyneuritis and stavation suggested the desirability of publishing the data obtained on rats under similar conditions. The preliminary report on the influence of fasting and of vitamin B starvation has been amplified and data have also been obtained on fasting rats to whom water (10 to 21 c.c. daily) was administered by stomach tube during the last days of the fast. Total solids were determined by an adaptation of Peters'method and the other constituents by the methods of Folin and Wu. From the summary given in the table it is apparent that the non-protein nitrogen of the blood of fasting rats is 30-40 per cent higher than that of normal animals, the increase being practically all in the urea fraction. Total dry matter, creatinine and creatine are slightly increased. Fasting rats that are given water per os during the last few days of their fast show normal values for non-protein nitrogen and solids. The blood of rats deprived of vitamin B also gives figures that are normal except that creatinine is at the fasting level and creatine slightly higher than the fasting figure; these differences have little if any significance in the present state of uncertainty with regard to blood creatine and creatinine determinations. Deprivation of vitamin B in contrast to fasting is not accompanied by an accumulation of nitrogenous end-products in the blood; whatever the ultimate cause of this increase may be in fasting, it is prevented by administration of water.