[Respiratory system response to cooling in subjects with single nucleotide polymorphism rs11562975 in gene of thermosensitive TRPM8 ion channel].

On the basis of genomic studies in subjects belonged to Russian ethnic group it was identified individuals with heterozygous genotype, containing the C-allele in single nucleotide polymorphism rs11562975, located in 6 exon of the gene encoding the temperature-sensitive ion channel TRPM8. Subjects with heterozygous genotype GC were characterized by not only increased sensation to cold but also hypometabolic response to local skin cooling and non-temperature activation of TRPM8 ion channel by menthol--decrease in total metabolism, pulmonary ventilation and coefficient of oxygen extraction. The subjects with homozygous genotype GG had a lower cold sensation and adequate response to local skin cooling in respect to thermoregulation--decrease in respiratory heat loss and increase in the lipid metabolism.

[Effect of alpha2-adrenergic receptor antagonist yohimbine on thermoregulatory responses to cooling].

Ionoforetic yohimbine application to skin has a modulating effect on the thermoregulatory parameters. In thermoneutral conditions, yohimbine increases heat production and heat dissipation. At subsequent cooling, yohimbine facilitates the initiation of vascular and metabolic response by reducing the temperature threshold of both nonshivering and shivering thermogenesis. Under the influence of yohimbine the maximum value of both vascular and metabolic response increases. In strengthening the metabolic response the skeletal muscles shivering significantly contributes. In contrast to yohimbine, the norepinephrine thermogenic effect occurs by strengthening nonshivering thermogenesis. Features of the yohimbine influence on thermoregulatory parameters due to the dual localization and function of the alpha2-adrenergic receptors.

[Effect of TRPM8 ion channel activation on thermoregulatory response to cooling].

In rats, the effect of activation of the cold- and menthol-sensitive TRPM8 ion channel on different thermoregulatory parameters: total oxygen consumption, carbon dioxide release, respiration coefficient, constriction response of skin blood vessels, muscle activity, was studied. Activation of TRPM8 with menthol even in thermoneutral conditions produces an increase in oxygen consumption and a decrease in respiratory coefficient, which may suggest enhanced non-shivering thermogenesis and lipolysis. Rapid cooling against the background of TRPM8 activation is characterized by a decrease in the temperature thresholds of all thermoregulatory responses without associated changes in sequences of their initiation as well as in enhancement of metabolic component of emergency thermogenesis which leads to improved maintenance of core temperature in conditions when external cold acts on the organism. The obtained data on the effect of TRPM8 activation on metabolic parameters in thermoneutral conditions and under cooling suggest acontinuous involvement of this receptor in regulation of total metabolism and, possibly, in determination of the type of organism's metabolism as well as in determination of organism's response to external cooling.

[Relationship of single-nucleotide polymorphism rs11562975 in thermo-sensitive ion channel TRPM8 gene with human sensitivity to cold and menthol].

The examination of people belonging to the Russian ethnic group revealed that 20.3% of subjects had heterozygous genotype, containing the C-allele in single nucleotide polymorphism rs11562975, located in exon 7 of the gene encoding the temperature-sensitive ion channel TRPM8. Functional differences, associated with sensitivity to cold and menthol were identified between subjects with different genotypes of the polymorphism rs11562975 (GG and GC). Subjects with heterozygous genotype GC were characterized by increased sensitivity to cold and reduced sensitivity to menthol, agonist of the ion channel TRPM8, compared with subjects with homozygous genotype GG.

[Effect of rapid and slow cooling on thermoregulatory responses in hypertensive and normotensive rats after calcium administration].

The effect of iontophoretic administration of calcium ions to skin in the area of cold stimulus application on the thermal thresholds and the magnitude of cold defense responses in normotensive Wistar and hypertensive ISIAH rats was studied. In thermoneutral conditions, administration of calciumions wos without effect on the measured thermoregulatory parameters. Under the effect of calcium, the thresholds of all the thermoregulatory responses to cooling (such as heat loss, oxygen consumption, shivering) are lowered and the values of heat loss and shivering thermogenesis are considerably increased. The effects of calcium on thermoregulatory responses depend on the rate of cooling. All changes are more expressive in hypertensive rats. The increased sensitivity of hypertensives to calcium suggests that change in their calcium metabolism may be a cause of the observed shifts in the thermoregulatory response to cold.

[The functional modifications under the long-term adaptation to cold]. / Funktsional'nye izmeneniia pri adaptatsii organizma k kholodu.

The data on modifications and interrelation of the afferent and efferent parts of the thermoregulatory system under the long-term adaptation to cold are presented. The body of data evidences for the important role of the thermoreceptors in the adaptive changes of the cold-defense responses.

[Characteristics of responses of the sympatho-adrenal system to various types of cooling]. / Osobennosti reaktsii simpatoadrenalovoi sistemy krys pri raznykh tipakh okhlazhdeniia.

Fast cooling involving the dynamic activity of the skin cold receptors seems to establish a condition for changes in catecholamine concentration at a lesser decrease of body temperature as compared with slow cooling.

[Effect of adaptation to cold and physical training on heat emission during muscle work]. / Vliianie adaptatsii k kholodu i fizicheskoi trenirovki na teplootdachu pri vypolnenii myshechnoi raboty.

People, for a long time exposed to cold and physical training or cold only, exhibit strengthening of thermal regulatory reactions aimed at the preservation of heat in the body in the state of rest, as well as during muscular tension. Adaptation of the organism to cold in the situation of limited motor activity lead to the increase of the thickness of the body "cover" under the conditions of rest in the cold due to the decrease of the temperature of skeletal muscles, while physical training in the cold facilitates stabilization of muscular temperature and, correspondingly, lessening of the thickness of the "cover". At the initial stage of muscular activity thermal regulatory reactions of the organism are aimed at the decrease in heat emission, which promotes accelerated heating of the muscles.

[Thermoregulatory effect of beta-adrenoreceptor block in the cold-adapted rat at rest and during exertion]. / Termoreguliatsionnyi éffekt blokady beta-adrenoretseptorov u adaptirovannykh k kholodu krys v pokoe i pri rabote.

Inderal does not affect the thermoregulatory system in thermoneutral conditions. Blockade of beta-adrenoreceptors at 6 degrees C decreases the oxygen consumption in cold-acclimated rats and reduces it down to the level of control animals. Cold-acclimated rats have the same level of work hyperthermia at different ambient temperatures (26 degrees C, 6 degrees C) and under inderal injection. Control animals can only the same in warm environment.

[Efficiency of muscle work in white rats adapting to cold]. / Issledovanie éffektivnosti raboty myshts u belykh krys pri adaptatsii k kholodu.

The correlation between heat production and muscular work with loads from 50 to 500 g was studied in white rats adapted to cold.