[The myogenic basis of smooth muscle motility (author's transl)].
Many mammalian smooth muscle tissues are able to produce spontaneous, myogenic activity. Five types of phasic-rhythmic activity can be distinguished: 1) Spikes: brief depolarizations of the membrane which trigger calcium release and contraction; 2) oscillations of the membrane potential of the second-rhythm type (SR) generating the spikes; 3) various organ-specific rhythms such as gastric and ureteral peristalsis which can be grouped together as basic organ-specific rhythms (BOR); 4) slower fluctuations of the minute-rhythm type (MR); 5) an hour-rhythm (HR) as the slowest type. In addition, some tissues generate tonic activity by special processes which can operate without spike discharges of the cell membrane. A selective blockade of phasic and tonic components is possible with some members of the group of so-called calcium antagonists. This indicates that two different calcium activation systems exist in the membrane of smooth muscle cells (P- and T-systems). Selective P- and T-blockade offers new possibilities for pharmacological influences on the smooth muscle system.
D000818:Animals; D005075:Biological Evolution; D002118:Calcium / Q000378:metabolism; D002415:Cats; D004285:Dogs; D006168:Guinea Pigs; D006801:Humans; D008564:Membrane Potentials; D009119:Muscle Contraction; D009129:Muscle Tonus; D009130:Muscle, Smooth / Q000502:physiology*; D010507:Periodicity; D011817:Rabbits; D051381:Rats; D013552:Swine
D002118:Calcium
Die myogene Basis der glattmuskulären Motorik.