[The depressant effect of fatty acids on the electrical and contractile activities of smooth muscles]. / Ugnetaiushchee vliianie zhirnykh kislot na élektricheskuiu i sokratitel'nuiu aktivnost' gladkikh myshts.

Inhibitory action of some fatty acids on the visceral and vascular smooth muscle of guinea pig and rat was studied by the sucrose-gap method. Potency of the inhibitory effects of fatty acids depended both on the carbon chain length and degree of saturation of acid molecule. The revealed inhibitory effect of some fatty acids (caprinic and oleinic) can be of essential physiological significance in regulation of excitation of smooth muscles.

[The generation of nonadrenergic inhibiting synaptic potentials in the smooth muscles of the gastrointestinal tract by substituting cesium ions for potassium ions]. / Generatsiia neadrenergicheskikh tormoziashchikh sinapticheskikh potentsialov v gladkikh myshtsakh zheludochno-kishechnogo trakta pri zamene ionov kaliia ionami tseziia.

Nonadrenergic inhibitory junction potentials (IJPs) evoked by intramural stimulation were investigated in smooth muscle of guinea pig stomach, caecum and colon by means of sucrose-gap method. IJPs disappeared in the smooth muscle preexposed to K-free Krebs solution for 4-9 h and restored by addition 6mM Cs+. The amplitude of IJPs was half as much as one in normal conditions but the latency and duration were significantly prolonged. In most cases apamin blocks IJPs in these muscles. The results presented suggest that IJPs generation is due to Cs+ ions permeated through Ca(2+)-activated apamin-sensitive potassium channels of small conductance in these conditions. As the responses to ATP were affected in parallel with IJPs, these results are consistent with the purinergic hypothesis.

[The role of osmotic factors in the effect of mineral water Naftusia on smooth muscles of the portal vein]. / Rol' osmoticheskogo faktora v deistvii mineral'noi vody naftisi na gladkie myshtsy vorotnoi veny.

The effect of the Krebs solution tonicity on the electrical and mechanical activity of smooth muscles has been studied while adding 1-5% volume of mineral water Naftusya, its artificial salt analog, and distilled water into the above solution. It is shown that effects observed are induced by the medium tonicity changes rather than by biologically active components of the mineral water. The smooth muscle cells of the rat portal vein are sensitive osmometers which affect hypotonic Krebs solution by 1%.

[Effect of strontium, barium and manganese ions on non-adrenergic inhibitory synaptic potentials and the action of ATP in the smooth muscle of the human intestine]. / Vliianie ionov strontsiia, bariia i margantsa na neadrenergicheskie tormoziashchie sinapticheskie potentialy i deistvie ATF v gladkikh myshtsakh kishechnika cheloveka.

The ionic mechanism of nonadrenergic inhibition in smooth muscles of human intestine was studied by the sucrose-gap method. The results obtained suggest that calcium-dependent potassium conductance which consists of apamin-sensitive and -insensitive components is involved in the action of nonadrenergic transmitter in smooth muscles of human intestine.

[Nature of non-adrenergic inhibition in the smooth muscles of the human intestine]. / Priroda neadrenergicheskogo tormozhaniia v gladkikh myshtsakh kishechnika cheloveka.

Electrical responses of longitudinal and circular smooth muscles of human small intestine and colon to ATP, alpha, beta-methylene-ATP, beta, gamma-methylene-ATP and adenosine were studied by the sucrose-gap method. In most cases ATP induced the effect similar to that of stimulation of the nonadrenergic inhibitory nerves. Desensitization of the purinergic receptors by alpha, beta-methylene-ATP selectively decreased the amplitude of inhibitory junction potentials. The results confirm the purinergic hypothesis of the nonadrenergic inhibition in human intestine.