[Comparative effects of menthol and icilin on the induced contraction of the smooth muscles of the vas deferens of normal and castrated rats].

Non-specific TRPM8 agonist menthol was shown to inhibit voltage- and agonist-evoked contractions of the smooth muscle (SM) of rat vas deferens. Here we compared the action of menthol with the action of more specific TRPM8 agonist icilin on depolarization- (60 mM KCl), carbachol-(CCh) and noradrenalin-(Nor)-evoked contractions of the SM strips from the prostatic and epididymal portions of the vas deferens of normal and castrated (60-137 days) rats. Inhibitory action of menthol (100 microM) and icilin (10 microM) on the amplitude of KCl-, CCh- and Nor-induced contractions of normal as well as castrated rats was similar consisting about 50%, despite castration per se strongly potentiated CCh- and Nor-evoked contractions compared to the control animals.

[Modulation of the smooth muscle contractions of the rat vas deferens by TRPM8 channel agonist menthol].

TRPM8 is nonselective, Ca2- permeable cationic channel, which is activated by innocuous cold and by chemical drugs imitators of cooling, menthol, icilin and cucalyptol. TRPM8 expression was detected in the smooth muscle cells of the rat vas deference with preferential localization of the TRPM8 protein to the membrane of sarcoplasmic reticulum (SR). In the present work we have studied the effects of TRPM8 channel agonist, menthol, on the contractions of the smooth muscle strips of the epididimal and prostatic portions of the rat vas deferens evoked by potassium rich (KCl) Krebs solution and by muscarinic or adrenergic agonists carbachol (CCh) or noradrenalin (Nor).

[Study of the recovery rate of non-NMDA desensitized receptors of hippocampal neurons using paired and rhythmic application of glutamate].

The new technique has been used to realize paired short-term application of glutamate to whole dialyzed neuron. Desensitization of receptors via first application of glutamate resulted in incomplete recovery of the current evoked by the second application if interval between both applications was less than 160 ms. The recovery time constant of the current was found to be 44 ms at single exponential approximation.

[Effects of short-term application of glutamate-containing solution on isolated rat hippocampal neurons].

The "concentration clamp" technique has been modified to realize fast and short-term application of a transmitter to whole neuron followed by its fast washout. Prolonged glutamate application evoked activation of the desensitized current. The application time was shortened to intervals when the washout corresponded to unfinished desensitization of the current.

[Action of the leukotriene LTC4 on the calcium channels of the somatic membrane of the nerve cell and tone of smooth muscle organs].

Effects of synthetic leukotriene LTC4 on the internally perfused voltage-clamped snail neurons as well as on the electrical and mechanical activities of the stomach smooth muscle cells were studied. It was found that LTC4 increased calcium inward current in the soma membrane of a cell by activation of both voltage and receptor operated Ca-channels. LTC4 was effective only from outside but not from inside of the membrane which indicated that there was a receptor for leukotrienes in the neuronal membrane.