@article {Comtois1061, author = {A Comtois and P Light and J M Renaud}, title = {Effect of tolbutamide on the rate of fatigue and recovery in frog sartorius muscle.}, volume = {274}, number = {3}, pages = {1061--1066}, year = {1995}, publisher = {American Society for Pharmacology and Experimental Therapeutics}, abstract = {The goal of this study was to determine how blocking ATP-sensitive K+ channels with tolbutamide affects the excitability and contractility of intact frog sartorius muscle during fatigue development. Fatigue was elicited with one tetanic contraction every sec for 3 min. During fatigue the resting potential decreased by 10 mV although the action potential overshoot remained constant. The addition of 2 mmol.liter-1 tolbutamide 60 min before fatigue did not modify the effect of fatigue on the resting potential and action potential overshoot. During fatigue development the half-repolarization time of control muscles increased by 0.26 msec in control muscles, although it increased by 0.77 msec in the presence of 2 mmol.liter-1 tolbutamide; the difference was significant. The decrease in force during fatigue development was not affected by 2 mmol.liter-1 tolbutamide (added 60 min before fatigue), whereas the recovery of force after fatigue was slower in tolbutamide- exposed muscles than in control muscles. Addition of 2 mmol.liter-1 tolbutamide after 5 min of recovery reduced the recovery rate of the resting potential and half-repolarization time, but did not affect the recovery of tetanic force during the first 40 min. Our results are consistent with the hypothesis that ATP-sensitive K+ channels are activated during fatigue development and that they contribute to the repolarization phase of action potentials, but they do not support the hypothesis that ATP-sensitive K+ channels contribute to the decrease in force.}, issn = {0022-3565}, URL = {https://jpet.aspetjournals.org/content/274/3/1061}, eprint = {https://jpet.aspetjournals.org/content/274/3/1061.full.pdf}, journal = {Journal of Pharmacology and Experimental Therapeutics} }