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.