Effects of birth on energy metabolism in the rat kidney.
The oxygen-consumption rates and the activities of fumarase and beta-hydroxyacyl-CoA dehydrogenase were compared in mitochondria isolated from fetal- and neonatal-rat kidney. Whole-organ ATP, phosphocreatine and creatine contents were determined in parallel. Kidney mitochondrial respiratory rates in the presence of succinate, glutamate/malate and palmitoyl-L-carnitine increased between 21 days post coitum and 1 day post partum, together with activities of oxidative enzymes. However, this postnatal maturation of oxidative metabolism was not yet initiated in mitochondria isolated from kidney 1 h post partum. An increase in ATP and phosphocreatine was observed immediately after delivery; newborn-rat kidney ATP content then remained high, whereas phosphocreatine reserves decreased considerably between 6 h and 1 day post partum. It is concluded that the increase in high-energy phosphate compounds observed at birth is not initially related to an activation of oxidative phosphorylation, and probably involves a transient stimulation of anaerobic glycolysis, while a progressive mitochondrial maturation takes place in the rat kidney during the first day of newborn life.
Laboratoire de Différenciation Fonctionelle, Université Paris, France.
J
J
Bastin
E
E
Delaval
N
N
Freund
M
M
Razanoelina
F
F
Djouadi
J
J
Bismuth
J P
JP
Geloso
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D003401:Creatine / Q000378:metabolism; D004734:Energy Metabolism; D005649:Fumarate Hydratase / Q000378:metabolism; D007668:Kidney / Q000196:embryology / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D010101:Oxygen Consumption; D010172:Palmitoylcarnitine / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D010725:Phosphocreatine; D010172:Palmitoylcarnitine; D000255:Adenosine Triphosphate; D015094:3-Hydroxyacyl CoA Dehydrogenases; D005649:Fumarate Hydratase; D003401:Creatine