Mitochondrial oxidative phosphorylation in saponin-skinned human muscle fibers is stimulated by caffeine.
The addition of 15 mM caffeine to saponin-skinned human muscle fibers from M. vastus lateralis caused in the presence of 2 mM ATP an approx. 2-fold stimulation of respiration with glutamate+malate. This effect can be abolished by either the addition of the Ca2+ chelator EGTA, the inhibitor of Ca2+ transport Ruthenium red and the inhibitor of the myosin ATPase vanadate. The caffeine concentration dependency of respiration of fibers coincided with the caffeine-caused stimulation of myosin ATPase activity. The activation of oxidative phosphorylation in saponin-skinned human muscle fibers by caffeine can be explained by a stimulation of myosin ATPase caused by Ca2+ release from sarcoplasmic reticulum.
Institut für Biochemie, Medizinische Akademie Magdeburg, Germany.
W S
WS
Kunz
A V
AV
Kuznetsov
F N
FN
Gellerich
D002110:Caffeine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D009218:Myosins / Q000378:metabolism; D010085:Oxidative Phosphorylation / Q000187:drug effects*; D010100:Oxygen / Q000378:metabolism; D012503:Saponins / Q000494:pharmacology*; D012519:Sarcoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism
D012503:Saponins; D002110:Caffeine; D009218:Myosins; D010100:Oxygen; D002118:Calcium