AJP - Renal Physiology, Vol 252, Issue 1 91-F98, Copyright © 1987 by American Physiological Society
Effects of hypoproteinemia on renal hemodynamics, arterial pressure, and fluid volume
R. D. Manning Jr
The effects of long-term hypoproteinemia on renal hemodynamics, arterial
pressure, and fluid volume were studied in eight conscious dogs over a
34-day period. Plasma protein concentration (PPC) was decreased by daily
plasmapheresis, and the effects of decreasing and increasing sodium intake
were measured. By the 12th day of plasmapheresis, during which sodium
intake was 30 meq/day, PPC had decreased to 2.5 g/dl from a control value
of 7.2 g/dl, mean arterial pressure had decreased to 78% of control,
glomerular filtration rate (GFR) was 75.2% of control, and urinary sodium
excretion was decreased. By day 18 of plasmapheresis, estimated renal
plasma flow (ERPF) was decreased to 60% of control due to the decreased
arterial pressure and an increase in renal vascular resistance. Also,
plasma renin activity and plasma aldosterone concentration were both
increased, and the relationship between mean arterial pressure and urinary
sodium excretion was distinctly shifted to the left along the arterial
pressure axis. In contradistinction to acute experiments, chronic
hypoproteinemia results in decreases in GFR, ERPF, and urinary sodium
excretion and has marked effects on both fluid volume and arterial pressure
regulation.
