Abstract
The well documented Ca contracture or Ca rigor of the frog's ventricle due to excess Ca in the medium was found to be accompanied by rapid regular electrical oscillations (“rigor oscillation”).Not only an increase in the Ca content of the ventricle beyond a certain limit, but also the excitation conducted from the auricle were found necessary for the induction of the rigor.The rigor was interrupted by the A-V block due to hypoxia during the state of rigor, and reappeared after recovery of the conduction.
The K in the medium antagonized the rigor by inhibiting the increase in the cellular Ca content.
