Does growth hormone treatment alter skeletal muscle mitochondrial respiration in rats?
OBJECTIVE
Growth hormone (GH) has been shown to stimulate lipolysis and enhance lipid oxidation. We investigated whether GH could improve mitochondrial oxidative capacity.


METHODS
Fourteen male Wistar rats received 14-day treatment with biosynthetic human GH (10 IU/kg/24 h) or placebo. Mitochondria were isolated from the total muscle of one hind limb of the rat. Mitochondrial oxygen consumption was measured in vitro using a Clark-type electrode with three substrates: palmitoyl-L-carnitine, pyruvate and succinate (+ rotenone).


RESULTS
Muscle mitochondrial yield was not significantly different in the GH-treated group from that in controls. Neither the basal nor ADP-stimulated respiratory state reached a significant difference between the 2 groups with palmitoyl-L-carnitine, pyruvate, and succinate.


CONCLUSIONS
GH treatment did not improve the oxidative capacity of skeletal muscle mitochondria.
Peyreigne
C
C
Département de Physiologie, Laboratoire de Physiologie des Interactions, UPRES EA701, Institut de Biologie, Faculté de Médecine, Montpellier, France. c.peyreigne@laposte.net
Raynaud
E
E
Fedou
C
C
Prefaut
C
C
Brun
J-F
JF
Mercier
J
J
D000244:Adenosine Diphosphate / Q000378:metabolism; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D013006:Growth Hormone / Q000494:pharmacology*; D006801:Humans; D050356:Lipid Metabolism; D008297:Male; D008931:Mitochondria, Muscle / Q000187:drug effects / Q000378:metabolism*; D009124:Muscle Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D009245:NADH Dehydrogenase / Q000378:metabolism; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar
D009124:Muscle Proteins; D000244:Adenosine Diphosphate; D013006:Growth Hormone; D009245:NADH Dehydrogenase