title: Dietary protein intake conditions the degree of renal vasoconstriction in acute renal failure caused by ureteral obstruction.
abstract: Whole kidney inulin (CIn) and PAH (CPAH) clearances were measured after unilateral release of bilateral ureteral obstruction (BUO) of 24-h duration in rats fed for 4 wk isocaloric diets containing either 40% casein (high protein diet) or 6% casein (low protein diet). Values for CIn and CPAH were markedly depressed in both groups but to a greater extent in high protein-fed rats, averaging less than 60% of values measured in low protein-fed animals. Captopril, an inhibitor of the angiotensin I converting enzyme, increased CIn and CPAH markedly but comparably in high or low protein fed rats. Micropuncture studies performed after unilateral release of BUO in another group of rats fed a high or a low protein diet revealed lower levels of glomerular plasma flow rate (QA) and single nephron glomerular filtration rate (SNGFR) in rats fed a high protein diet. Values for renal arteriolar resistances were nearly twofold in high as compared with low protein-fed animals. Infusion of OKY-1581, an inhibitor of thromboxane A2 synthetase, increased both QA and SNGFR, decreased arteriolar resistances, and increased glomerular capillary ultrafiltration coefficient in high but not in low protein-fed rats. Urinary thromboxane B2 excretion per milliliter of GFR was greater in rats fed a high protein diet than in those fed a low protein diet after release of BUO but not in normal rats. In normal rats infusion of OKY-1581 did not increase CIn or CPAH.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology; D000818:Animals; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D005919:Glomerular Filtration Rate; D007668:Kidney / Q000098:blood supply*; D051381:Rats; D011919:Rats, Inbred Strains; D012079:Renal Circulation; D013928:Thromboxane A2 / Q000378:metabolism; D013997:Time Factors; D014517:Ureteral Obstruction / Q000150:complications*; D014655:Vascular Resistance; D014661:Vasoconstriction
chemical_list: D004044:Dietary Proteins; D013928:Thromboxane A2