AJP - Renal Physiology, Vol 252, Issue 6 1088-F1094, Copyright © 1987 by American Physiological Society
High protein intake stimulates glomerular prostaglandin formation in remnant kidneys
R. A. Stahl, S. Kudelka and U. Helmchen
Reduction of renal mass in the rat results in an increased glomerular
prostaglandin (PG) and thromboxane (TX) formation that modulates renal
hemodynamics. To evaluate whether dietary protein intake could exert
effects on renal PG and TX formation after reduction of approximately 70%
of renal mass, rats with remnant kidneys were placed on either a
high-protein (HP) or a low-protein (LP) diet. After 2 wk on the diet,
proteinuria, glomerular filtration rate (GFR), urinary PGE2 excretion, and
glomerular PGE2, 6-keto PGF1 alpha, and TxB2 biosynthesis were
significantly greater in the rats on HP diets. Two-wk administration of the
thromboxane synthesis inhibitor UK 38485 reduced renal TxB2 formation by
approximately 70%. In addition, chronic UK 38485 treatment significantly
inhibited papillary PGE2 production. Neither chronic nor bolus
administration of UK 38485 had an effect on proteinuria or GFR in rats on
HP diets. Chronic UK 38485 treatment, however, reduced GFR and proteinuria
in rats on LP diets. The bolus administration of UK 38485 did not alter GFR
in animals receiving a LP diet. The cyclooxygenase inhibitor indomethacin
reduced GFR only in rats on HP diets. The data demonstrate that HP intake
stimulates renal prostanoid formation. The increased prostaglandin
formation on HP intake modulates GFR in these rats.
