Selective utilization of L-isomer of lactate in the smooth muscle of the guinea pig taenia caeci.
Utilization of D- and L-lactate in the isolated intestinal smooth muscle of the guinea pig taenia caeci was examined by measuring contractile tension, oxygen consumption, and adenosine triphosphate (ATP) and creatine phosphate (PCr) concentrations. In the absence of glucose in the medium, muscle contraction induced by a high concentration of K+ was inhibited and the rate of oxygen consumption and the concentrations of ATP and PCr were decreased. Addition of glucose, L-lactate, and D,L-lactate, but not D-lactate, led to recovery of muscle contraction, rate of oxygen consumption, and ATP and PCr concentrations when the tissue had been incubated in the high K+, glucose-free solution. These results suggest that the isolated guinea pig taenia caeci selectively utilizes the L-isomer of lactate as a substrate for energy metabolism.
Endo
I
I
Terumo Technical R & D Division, Tokyo, Japan.
Suzuki
T
T
Takahashi
H
H
Karaki
H
H
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002432:Cecum / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007773:Lactates / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D010725:Phosphocreatine / Q000378:metabolism; D013237:Stereoisomerism
D007773:Lactates; D010725:Phosphocreatine; D000255:Adenosine Triphosphate; D005947:Glucose