Intrarenal Regulation of Glomerular Filtration Rate

GLOMERULAR filtration is of interest because it is the first step in urine formation and because the excretion rates of many substances are at least partially dependent on the amounts filtered across the glomerular membrane. The forces involved in glomerular filtration — glomerular capillary hydrostatic pressure, plasma oncotic pressure and intratubular hydrostatic pressure — suggest that glomerular filtration rate (GFR) is dependent on arterial blood pressure. But additional factors are clearly involved because GFR may not vary with changes in blood pressure.Within approximately 30 mm of mercury above and below normal, renal plasma flow and GFR are held nearly . . .