An increase in which pressure would result in a decreased GFR?

Increased glomerular capillary oncotic pressure would lead to a decreased glomerular filtration rate (GFR) due to its effects on fluid dynamics within the glomerulus. Glomerular filtration relies on the balance of pressures: hydrostatic pressure (which pushes fluid out of the capillaries) and oncotic pressure (which draws fluid back into the capillaries).

When glomerular capillary oncotic pressure increases—often due to increased plasma protein concentrations—it pulls more fluid back into the capillaries from the Bowman’s space. This opposition to the hydrostatic pressure decreases the net driving force for filtration, thereby reducing the GFR.

This relationship highlights the delicate balance of pressures necessary for effective filtration in the kidneys and supports the concept of how changing oncotic pressure can directly affect renal function.