Birth induces rapid increases in mitochondrial oxidative enzymes
and na-k-atpase in proximal convoluted tubule of rat nephron.
Wijkhuisen, A., F. Djouadi, J. Vilar, C. Merlet-Benichou, and J.
Bastin.
INSERM U.319, Universit[acute]e Paris 7, 2 place Jussieu, 75251
Paris cedex 05, France
APStracts 3:0343C, 1996.
In the proximal convoluted tubule (PCT) of rat kidney, reabsorption is
known to take place during fetal life, but no data on Na-K-ATPase and
mitochondrial energy metabolism enzymes in this epithelium were
available at fetal and neonatal stages. Using quantitative
histochemistry approach, Na-K-ATPase, citrate synthase (Krebs cycle),
3-ketoacidCoA transferase and thiolase (ketone bodies oxidation),
[beta]-hydroxyacylCoA deshydrogenase (fatty acid oxidation), and
acetyl-carnitine transferase (acetylCoA transport through
mitochondrial membrane) were microassayed in PCT and metanephric
mesenchyme of fetal and newborn rat kidney. The data obtained
indicate that during fetal life, PCT differentiation involves
concomittant increases in Na-K-ATPase and oxidative enzyme
activities, supporting the hypothesis that mitochondria could play an
active role in cellular ATP turnover when reabsorptive functions
develop. Birth resulted in marked increases in the activities of Na
-K-ATPase and of fatty acid and ketone bodies oxidation enzymes in the
PCT, while no changes in enzyme activites occured in the metanephric
mesenchyme between the fetal and newborn stages.
Received 7 November 1995; accepted in final form 7 October 1996.
APS Manuscript Number C678-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 November 1996