[Anti-arrhythmia activity of crown-lactone I and its effect on aconitine-modified sodium channels]. / Antiaritmicheskaia aktivnost' kraun-laktona I i ego deistvie na modifitsirovannye akonitinom natrievye kanaly.

Antiarrhythmic activity of macrocyclic crown-lactone I as well as its effect on biological and model membranes were studied. Crown-lactone displaces the potential dependence of stationary inactivation of TTX-sensible sodium neurons currents towards more negative potentials reducing the modification of those characteristics by aconitine. Proceeding from the comparison between crown-lactone and known antiarrhythmic agents effect on sodium currents a conclusion is made that crown-ethers antiarrhythmic activity cannot be explained by the rhythmoinotropic effect.

[Effect of macrocyclic amidoesters on membranes]. / Vliianie makrotsiklicheskikh amidoéfirov na membrany.

A comparative analysis of new macrocyclic amidoesters effect on the bimolecular lipid membrane as well as on the electroexcitable membrane of snail isolated neurons was carried out. It was shown that the investigated complexes inducing a small change in lipid bilayer conductivity and some changes in Na-Ca neuron current characteristics produce essential changes of rapid potassium as well as late potassium current properties. It was concluded on the basis of these results and potassium compounds specificity that the investigated complexes interact directly with neuron potassium channels.

[Use of tonic contracture of strips of frog myocardium to study sodium-calcium exchange in the sarcolemma of myocardiocytes]. / Ispol'zovanie tonicheskoi kontraktury polosok miokarda liagushki dlia izucheniia natrii-kal'tsievogo obmena v sarkolemme kardiomiotsitov.

The mechanism of tonic component of the frog myocardium potassium contraction was studied. The degree of contraction depended on the potassium, sodium and calcium ions concentrations in extracellular medium. The tonic component of hyperpotassium contraction, as well as the additional contractions due to hyposodium and hypercalcium medium in the tonic component phase seems to stem from activation of sodium--calcium exchange. The latter through the sarcolemma of the heart cells was 3Na: 1Ca. The effect of some mono- and bivalent cations on sodium-calcium exchange in respect ot their inhibiting activity was as follows: Cd+2 greater than Sr+2 greater than Ba+2 greater than Mn+2 much greater than Mg+2 greater than Li+ greater than Cs+.

[Inhibition of Na+-Ca2+-exchange and superoxide dismutase activity of copper-containing cryptand complexes]. / Ingibirovanie Na+-Ca2+-obmena i superoksiddismutaznaia aktivnost' med'soderzhashchikh kriptandov.

It is shown that cryptand complexes containing copper inhibit sodium-calcium exchange in sarcolemma of cardiomyocytes. The complexes studied exhibit the superoxide dismutase activity. The binding of copper ions by cryptand prevents the development of cariotoxic effects of the former. Low toxicity, the combined superoxide activity and that inhibiting sodium-calcium exchange of cryptand complexes with copper (II) ions makes the further search for cardioprotective compounds perspective within the series of cryptand copper complexes.

[Circulating complexes of plasma fibronectin (fibronectin-fibrin) in human diseases]. / Tsirkuliruiushchie kompleksy plazmennogo fibronektina--fibronektin-fibrin pri nekotorykh zabolevaniiakh cheloveka.

The study of circulating complexes fibronectin-fibrin in 21 patients with immunocomplex affections revealed their high levels which occurred in inverse relationships with fibronectin concentrations in the blood, but in direct correlation with indicators of inflammation (fibrinogen, cialic acid). It is suggested that the complexes are involved in the development of fibrosis at the sites of chronic inflammation in immune disorders.

[Effect of the macrocyclic polyether 15-crown-5 on the ionic permeability of excitable membranes]. / Vliianie makrotsiklicheskogo poliéfira 15-kraun-5 na ionnuiu pronitsaemost' vozbudimykh membran.

The macrocyclic polyether 15-crown-5 at a concentration of 5 . 10(-5)-10(-3) M reduced the frequency of the contractions of an isolated rat auricle, increasing the refractory period of the contractions. The polyether lowered the rate of activation of the slow input current of rat spinal ganglionic neurons and blocked the sodium channels of the electroexcitable membrane without disturbing the function of activation and inactivation mechanisms. The compound under study considerably delayed the onset of and decelerated reactivation of the sodium input current. These actions were calcium-dependent, becoming more demonstrable with reduction of Ca2+ concentration outside the cell. 15-Crown-5 interfered with the action of Ca2+ on the lipid bilayer membrane potential. It is assumed that all the effects described are determined by the formation of 15-crown-5-Ca2+ complexes, thereby leading to the impairment of the packing of the membrane lipoprotein matrix.

[Effect of polymethylene- and polyhydroxyethylene-bis-(2-amino-1,3-diazepinium) iodides on cell and model membranes]. / Vliianie polimetilen- i polioksiétilen-bis(2-amino-1,3--diazepinii)-iodidov na kletochnye i model'nye membrany.

The effect of polymethylene- and polyoxyethylene-bis-(2-amino-1, 3-diazepinium) iodides on the membranes of neuromuscular synapsis and mitochondria as on the artificial membranes was studied. The compounds examined were shown to change the amplitude and kinetics of postsynaptic membrane responses to acetylcholine. Inhibition of end plate potentials and oxidative phosphorylation of mitochondria with different derivatives of diazepinium correlated with changes in the surface potential of the artificial phospholipid membrane. It is concluded that the derivatives of diazepinium directly interact with ionic channels of the acetylcholine-activated postsynaptic membrane.

[Physiological activity of polymethylene and polyoxyethylene bis-(2-amino-1,3-diazepiniuim) iodides]. / Fiziologicheskaia aktivnost' polimetilen- o pilioksiétilen-bis- -(2-amino-1,3-diazepinii)iodidov.

A study was made of physiological activity of a series of new bisquaternary compounds in which the role of cation heads is played by the residues of 2-amino-1,3-diazepinium. Studies performed on a frog neuromuscular preparation showed that the compounds under test effectively block the responses of the postsynaptic membrane to acetylchinoline. The derivatives of diazepinium have pronounced hypotensive and ganglion-blocking properties. Octamethylene-bis-(2-amino-1,3-diazepinium) iodide that appeared to be the most effective of the compounds under test compares very favourably with benzohexonium. It was found to be 1.5 times more powerful as regards the ganglion-blocking and hypotensive activity.