Time‐dependent and indirect effect of inorganic phosphate on force production in rat gastrocnemius exercising muscle determined by 31P‐MRS

FEBS Letters

Cozzone, Patrick J¹  Giannesini, Benoı̂t¹  Izquierdo, Marguerite¹  Bendahan, David¹  Confort-Gouny, Sylviane¹ 

[1] Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS 6612, Faculté de Médecine de Marseille, 27 Boulevard Jean Moulin, 13005 Marseille, France

关键词: Rat skeletal muscle;    Fatigue;    Electrical stimulation;    31P-Magnetic resonance spectroscopy;    Inorganic phosphate;    Calcium;   

DOI  :  10.1016/S0014-5793(01)02942-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The relationship of inorganic phosphate (P_i) and its diprotonated form (H₂PO₄ ⁻) to isometric force (F) was analyzed non-invasively using ³¹P-magnetic resonance spectroscopy. Rat gastrocnemius muscles were electrically stimulated at six different frequencies in order to produce different levels of fatigue. A curvilinear relationship was demonstrated between force production and [P_i] and [H₂PO₄ ⁻] accumulation. [P_i] and [H₂PO₄ ⁻] were correlated with F at the end of the stimulation period but not when F was maximal at the early stage of the stimulation period. Interestingly, the respective [P_i] and [H₂PO₄ ⁻] did not differ significantly between these two stages demonstrating that [P_i] and [H₂PO₄ ⁻] cannot be considered as direct effectors of fatigue. This time-dependent and indirect effect of [P_i] and [H₂PO₄ ⁻] on force production might be mediated by calcium ions.

【 授权许可】

Unknown