Muscle Fatigue and the Role of Transverse Tubules

Abstract
[Frog sartorius] skeletal muscle stimulations for 300 pulses, either as single twitches or as tetani, increases the amount of Ca extracted in a Ringer solution containing Sr. The Sr is used to prevent reuptake of Ca by the transverse tubules. The accumulation of Ca in the transverse tubules during stimulation may account for muscle fatigue.