RELATIONS OF EFFECTIVE RENAL BLOOD FLOW AND GLOMERULAR FILTRATION TO TUBULAR EXCRETORY MASS IN NORMAL MAN 1

Abstract

Data on the diodrast and inulin clearances, and on the maximal rate of tubular excretion of diodrast (diodrast Tm) and the maximal rate of tubular reabsorption of glucose (glucose Tm) are pre-sented for a series of normal [male][male] and [female][female]. Diodrast Tm, a measure of the total quantity of tubular excretory tissue in the kidney, is conceived to be roughly proportional to the total quantity of renal parenchyma. Statistical analysis of the data reveals that both the diodrast and inulin clearances increase in proportion to diodrast Tm, and that comparison of clearances in different individuals is more accurate when made on the basis of diodrast Tm than when the absolute values of the clearances are considered alone. This method of comparison is functionally equivalent to expressing the renal plasma or whole blood flow and the filtration rate on the basis of unit mass of renal parenchyma. The significance of the mean values of the diodrast clearance, etc., is discussed in relation to the possible perturbation of renal blood flow by factors involved in the clearance procedure, such as inulin and diodrast, and by selection of subjects, hydration and psychic influences. The data apparently accurately reflect the renal blood flow under "standard" conditions which closely approach the ordinarily accepted concept of basal conditions in the systemic and renal circulation.