Cellular adenosine triphosphate production and consumption in the descending thin limb of Henle's loop in the rat.
To characterize the properties of cellular adenosine triphosphate (ATP) production and consumption in the descending thin limb of Henle's loop (DTL) in rats, we measured the cellular ATP content by applying the microchemiluminescence method. For ATP production, isolated DTL from the short- and long-loop nephron (SDL and LDL, respectively) was incubated with several substrates such as alanine, glucose, glutamine, beta-hydroxybutyrate (beta-HBA), lactate, and pyruvate; for ATP production from each substrate indicated that glucose and pyruvate were the preferred substrates to maintain cellular ATP in both SDL and LDL. ATP production from glutamine, beta-HBA, and lactate was substantial in LDL. In SDL, glutamine was the preferred substrate, and beta-HBA and lactate were minimal. The utilization of alanine was minimal in both LDL and SDL. The cellular ATP was significantly restored by ouabain at concentrations of 1.5 x 10(-5) and 1.5 x 10(-3) M in LDL, but in SDL only at 1.5 x 10(-3) M. In both segments, the cellular ATP level was significantly decreased by monensin above the concentrations of 1 micrograms/ml in LDL and 5 micrograms/ml in SDL. From these observations, we conclude that there exist clear differences between LDL and SDL in ATP-supplying substrate specificities and ATP-consuming properties.
Department of Pharmacology, Faculty of Medicine, University of Tokyo, Japan.
K Y
KY
Jung
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H
Endou
D000255:Adenosine Triphosphate / Q000096:biosynthesis / Q000378:metabolism*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D007684:Kidney Tubules / Q000378:metabolism*; D008138:Loop of Henle / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008985:Monensin / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D011506:Proteins / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity; D013997:Time Factors
D011506:Proteins; D010042:Ouabain; D000255:Adenosine Triphosphate; D008985:Monensin