Non-selective cationic current--the basis of depolarization in smooth muscle

The activation of smooth muscle muscarinic receptors leads to its contraction. Electrophysiological and biochemical methods have gradually, over the time span of roughly 30-40 past years, helped to reveal this phenomenon's underlying processes. One element of this cascade of processes is the influx of cations into the smooth muscle cell--non-selective cationic current--causing depolarisation of the cell membrane and subsequent opening of voltage-operated calcium channels. This mini-review provides the reader with up-to-date knowledge on non-selective cationic current, supplemented with information on muscarinic receptors of smooth muscle, their coupling with effectors via G proteins, as well as on muscarinic modulation of calcium and potassium channels of smooth muscle. The conclusion is dedicated to pointing out the future trends of research in this area. (Tab. 2, Fig. 2, Ref. 82.)