The influence of streptozotocin-induced diabetes and the antihyperglycaemic agent metformin on the contractile characteristics and the membrane potential of the rat diaphragm.
After 2 months of streptozotocin-induced diabetes in rats, the membrane potential of the diaphragm muscle when measured in vitro at 30 degrees C was unchanged but the tetanic tension, the half-relaxation time of the isometric twitch and the fatigue resistance were each reduced. Treatment of the diabetic rats with the antihyperglycaemic agent metformin prevented the decrease in half-relaxation time and the greater degree of fatigue in the diaphragms. The possibility that changes in H+ and cyclic AMP concentrations in the diabetic muscles contributed to the decreased contractile function and that metformin acted by attenuating these changes is discussed.
Department of Physiology, Royal College of Surgeons in Ireland, Dublin, Ireland.
M
M
McGuire
M
M
MacDermott
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D003964:Diaphragm / Q000187:drug effects; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007537:Isometric Contraction / Q000187:drug effects; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D008687:Metformin / Q000494:pharmacology*; D018763:Muscle Fatigue / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
D007004:Hypoglycemic Agents; D008687:Metformin