[Electrical and contractile activity of the lymphangions of the mesenteric lymphatic vessels].

The electrical activity of smooth muscle of isolated lymphangiomas revealed spontaneous APs about 3.8 +/- 1.3 mV for 200-250 ms preceding the contractions. In Ca-free solution the APs and the contractions disappeared. The blockade of calcium channels suppressed electrical activity of smooth muscle cells. The increase of amplitude and time of the APs increased the amplitude and time of the contractions. The data suggest that spontaneous APs play a part in activation and coordination of the phasic contractions, and show that automaticity of lymphangiomas is revealed in smooth muscle cells of the circular layers of the valves, and that tonic and phasic contractions have a special type of membrane activating mechanisms.