Significance of Glomerular Perfusion in Relation to Variability of Filtration Rate

Abstract

Glomerular filtration rate (GFR) was reduced in dogs by 3 methods: (1) partial obstruction of the aorta by inflation of a balloon at the end of a cardiac catheter above the origins of the renal arteries, (2) step-wise reduction of blood pressure by controlled bleeding, and (3) dehydration. The GFR was increased by the infusion of large volumes of physiol. saline. GFR and glucose Tm values were determined and there was no consistent change in glucose Tm values with change in GFR. It was concluded that alterations in GFR are brought about in large part by alterations in the quantity of filtrate formed in each glomerulus, and that under normal conditions all glomeruli are functional and no reserve of inactive nephrons exists.