Transport and utilization of alpha-ketoglutarate by the rat kidney in vivo.
In order to establish the characteristics of net renal transport and utilization of alpha-ketoglutarate (alpha-KG) in the rat, we have precisely quantified the renal blood flow, the urinary flow and the rates of alpha-KG delivery, filtration, reabsorption or secretion, excretion, uptake or production by an in vivo rat kidney preparation. In normal rats, alpha-KG uptake was higher than alpha-KG reabsorption at both endogenous and elevated plasma alpha-KG concentrations; thus, a net peritubular transport, which was the main supplier of alpha-KG to the renal cells, took place. Saturation of reabsorption and peritubular transport of alpha-KG occurred at blood alpha-KG concentrations about 30 and 150 times above normal, respectively. Acute metabolic acidosis was found to have no effect on renal handling of alpha-KG. At endogenous plasma alpha-KG concentrations, alkalosis converted net renal uptake into net renal production of alpha-KG resulting in addition of alpha-KG by the renal cells both to blood and to the luminal fluid. Elevation of blood alpha-KG concentration restored the renal uptake of alpha-KG. This uptake, which was entirely accounted for by the peritubular transport of alpha-KG, reached a maximum which was lower than that observed in normal and acidotic rats.
Martin
M
M
Institut National de la Santé et de la Recherche Médicale (U 80), Lyon, France.
Ferrier
B
B
Baverel
G
G
D000136:Acid-Base Equilibrium; D000138:Acidosis / Q000378:metabolism; D000471:Alkalosis / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D007656:Ketoglutaric Acids / Q000097:blood / Q000378:metabolism* / Q000652:urine; D007668:Kidney / Q000098:blood supply / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012077:Renal Artery
D007656:Ketoglutaric Acids