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.
McGuire
M
M
Department of Physiology, Royal College of Surgeons in Ireland, Dublin, Ireland.
MacDermott
M
M
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