Dependence of Glomerular Filtration Rate on Proximal Tubular Reabsorption of Salt

L eyssac , P. P. Dependence of glomerular filtration rate on proximal tubular reabsorption of salt. Acta physiol. scand. 1963. 58. 236–242. — The purpose of the present investigation was to study the relationship between the rate of glomerular filtration and the rate of proximal tubular reabsorption of filtrate in mammalian kidneys. In the exposed left kidney of white rats the time required from ligation of the left renal artery until the proximal tubules have completed reabsorption of the luminal filtrate and the tubules have thus become occluded was observed. This time interval, named“occlusion time”, observed directly in a stereomicroscope, was measured with a stop watch and could be determined within plus or minus 2 sec. Inulin clearances were determined in periods immediately preceding the measurement of the occlusion time. A linear correlation was demonstrated between glomerular filtration rate and occlusion time, and it is concluded that the proximal reabsorption of sodium is a T‐max type of process independent of but limiting the glomerular filtration rate.