Abstract
The activities of enzymes of the tricarboxylic acid cycle were measured in order to compare the respiratory capacity in different parts of the nephron of the rat. Oxoglutarate dehydrogenase, citrate synthase and isocitrate dehydrogenase were assayed in single nephron segments dissected out of freeze-dried cryostat sections. The activities of the three enzymes per unit weight are higher in the distal segments (thick ascending limb and distal convoluted tubule) than in the proximal tubule. The distal vs. proximal ratios of activities are about 1.5, 2.5 and 2 for oxoglutarate dehydrogenase, citrate synthase and isocitrate dehydrogenase, respectively. Oxoglutarate dehydrogenase shows the lowest activities along the whole nephron and appears to catalyze the rate-limiting step of the tricarboxylic acid cycle. The possibility to estimate the respiratory capacity in the different segments of the nephron on the basis of the activity of oxoglutarate dehydrogenase is discussed. The capacity calculated for the proximal tubule (between 44 and 66 μmol O · min−1 · g−1, depending on the substrate) is in agreement with direct measurements of oxygen consumption as well as with calculations made on the basis of morphometrical data.
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References
Alp PR, Newsholme EA, Zammit VA (1976) Activities of citrate synthase and NAD+-linked and NADP+-linked isocitrate dehdrogenase in muscle from vertebrates and invertebrates. Biochem J 154:689–700
Balaban RS, Mandel LJ, Soltoff SP, Sotrey JM (1980) Coupling of active ion transport and aerobic respiratory rate in isolated renal tubules. Proc Natl Acad Sci USA 77:447–451
Burch HB, Narins RG, Chu C, Fagioli S, Choi S, McCarthy W, Lowry WH (1978) Distribution along the rat nephron of three enzymes of gluconeogenesis in acidosis and starvation. Am J Physiol 235:F246–F253
Cohen JJ, Kamm DE (1981) Renal metabolism: relation to renal function. In: Brenner BM, Rector FC (eds). The kidney, vol. I. WB Saunders Company, Philadelphia London Toronto, p 144
Guder WG, Schmidt U (1974) The localization of gluconeogenesis in the rat nephron: determination of phosphoenolpyruvate carboxykinase in microdessected tubules. Hoppe-Seyler's Z Physiol Chem 355:273–278
Harris SI, Balaban RS, Barret L, Mandel LJ (1981) Mitochondrial respiratory capacity and Na+- and K+-dependant adenosine triphosphatase-mediated ion transport in the intact renal cell. J Biol Chem 256:10319–10328
Hems DA (1976) Carbohydrate metabolism in relation to kidney function. In: Schmidt U, Dubach UC (eds) Renal metabolism in relation to kidney function. Hans Huber Publisher, Bern Stuttgart Vienna, p 26
Kato T, Berger SJ, Carter JA, Lowry OH (1973) An enzymatic cycling method for nicotinamide-adenine denucleotide with malic and alcohol dehydrogenase. Anal Biochem 53:86–97
Katz AI, Doucet A, Morel F (1979) Na-K-ATPase activity along the rabbit, rat and mouse nephron. Am J Physiol 237:F114–F120
Kiil F, Sejested OM, Steen PA (1980) Energetics and specificity of transcellular NaCl transport in the dog kidney. Int J Biochem 12:245–250
Lowry OH, Passonneau JV (1972) A flexible system of enzyme analysis. Academic Press, New York London
Lowry M, Ross BD (1980) Activation of oxoglutarate dehydrogenase in the kidney in response to acute acidosis. Biochem J 190:771–780
Marver D, Schwarz MJ (1980) Identification of mineralocorticoid target sites in the isolated rabbit cortical nephron. Proc Natl Acad Sci USA 77:3672–3676
Newsholme EA (1980) Reflections on the mechanisms of action of hormones. FEBS Lett 117 (Suppl):K121-K134
Newsholme EA, Crabtree B, Zammit VA (1980) Use of enzyme activities as indices of maximum rates of fuel utilization. In: CibaFoundation (eds) Trends in enzyme histochemistry and cytochemistry. Excerpta Medica, Amsterdam Oxford New York, p 245
Parvin R, Caramancion MNV, Pande SV (1980) Convenient rapid determination of picomole amounts of oxaloacetate and aspartate. Anal Biochem 104:296–299
Pette D, Hofer HW (1980) The constant proportion enzyme group concept in the selection of reference enzymes in metabolism. In: CibaFoundation (eds) Trends in enzyme histochemistry and cytochemistry. Excerpta Medica, Amsterdam Oxford New York, p 231
Pfaller W (1982) Structure function correlation on rat kidney. Adv Anat Embryol Cell Biol 70:1–106
Ross BD, Epstein FH, Leaf A (1973) Sodium reabsorption in the perfused rat kidney. Am J Physiol 225:1165–1171
Schmidt U, Horster M (1977) Na-K-activated ATPase: activity maturation in rabbit nephron segments dissected in vitro. Am J Physiol 233:F55–F60
Schurek HJ, Brecht JP, Lohfert H, Hierholzer K (1975) The basic requirements for the function of the isolated cell free perfused rat kidney. Pflügers Arch 354:349–365
Ullrich KJ (1979) Renal transport of organic solutes. In: Giebisch G, Tosteson DC, Ussing HH (eds) Membrane transport in biology, vol. IV. Springer, Berlin Heidelberg New York, p 413
Vinay P, Mapes JP, Krebs HA (1978) Fate of glutamine carbon in renal metabolism. Am J Physiol 234:F123–F129
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Supported by the Swiss National Science Foundation, Grant No. 3.900-0.79
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Le Hir, M., Dubach, U.C. Activities of enzymes of the tricarboxylic acid cycle in segments of the rat nephron. Pflugers Arch. 395, 239–243 (1982). https://doi.org/10.1007/BF00584816
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DOI: https://doi.org/10.1007/BF00584816