Dietary protein causes a decline in the glomerular filtration rate of the remnant kidney mediated by metabolic acidosis and endothelin receptors.
Dietary casein promotes a progressive decline in the glomerular filtration rate (GFR) of remnant kidneys associated with metabolic acidosis and an endothelin-mediated increase in renal acidification. We tested whether diets that affect the acid-base status contributes to the decline of GFR through endothelin receptors in rats with a remnant kidney. Rats on a casein diet had metabolic acidosis at baseline and developed a progressive decline in GFR after renal mass reduction. Dietary sodium bicarbonate but not sodium chloride ameliorated metabolic acidosis and prevented the decrease in GFR but only after the sodium bicarbonate-induced increase in blood pressure was treated. Dietary soy protein did not induce baseline metabolic acidosis and rats with remnant kidney on a soy diet had no decrease in their GFR. By contrast, rats with a remnant kidney on soy protein given dietary acid developed metabolic acidosis and a decreased GFR. This decline in GFR was prevented in either case by endothelin A but not endothelin A/B receptor antagonism. Our study suggests that the casein-induced decline in GFR of the remnant kidney is mediated by metabolic acidosis through endothelin A receptors.
Phisitkul
S
S
Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.
Hacker
C
C
Simoni
J
J
Tran
R M
RM
Wesson
D E
DE
D000138:Acidosis / Q000503:physiopathology*; D000818:Animals; D001639:Bicarbonates / Q000494:pharmacology; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000097:blood; D002364:Caseins / Q000009:adverse effects; D004044:Dietary Proteins / Q000009:adverse effects*; D019332:Endothelin-1 / Q000652:urine; D005919:Glomerular Filtration Rate; D008297:Male; D009392:Nephrectomy; D051381:Rats; D017466:Receptors, Endothelin / Q000502:physiology*; D012965:Sodium Chloride / Q000494:pharmacology
D001639:Bicarbonates; D002364:Caseins; D004044:Dietary Proteins; D019332:Endothelin-1; D017466:Receptors, Endothelin; D002245:Carbon Dioxide; D012965:Sodium Chloride