Comparison of the redox states of different tissues and the types of acetylcholine effect.

By simultaneous recording of myograms, cardiomyograms and tissue redox state potentials (RSP) it was established that in tissues with higher RSP levels (+170 mV or more; rectus muscle, smooth muscle of the stomach) acetylcholine (Ach) exerted a depolarizing type of action, while in the frog heart ventricle (with RSP values lower than +170 mV) the mediator triggered a hyperpolarizing type Ach effect. Since following an appropriate adjustment of RSP values by exogenous redox agents the depolarizing and/or hyperpolarizing Ach effects can be modelled on any organs, independently of the original type of effect of Ach, it may be assumed that the existing redox state plays an important role in the determination of the depolarizing and/or hyperpolarizing effect of Ach.