Although there have been extensive studies of the metabolism of fasting men and animals, as revealed by examinations of the urine and the expired air, comparatively little has been written concerning alterations in the concentration of various chemical constituents of the blood. During the last three years we have conducted thirty fasting periods in which we have measured various blood constituents. The most striking alteration of the blood was found to be a greatly increased concentration of uric acid. This observation, together with a study of the factors affecting uric acid retention during fasting, has been published.1 This article deals with observations on the concentration in the blood of nonprotein, urea and amino-acid nitrogen, sugar, cholesterol, fibrin, inorganic phosphorus, total calcium and plasma bicarbonate. Observations concerning chlorides will be presented elsewhere.
MATERIAL AND METHODS
Of the thirty fasting periods, twenty-four were of persons who were fasted as a therapeutic measure