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Biomedical subjects

Iu F Pastukhov

Publications and source records attributed to Iu F Pastukhov.

At least 19 recordsLinked to original sources
PubMed1985

[Intradiurnal organization of the wakefulness-sleep cycle and energy metabolism in rats exposed to low ambient temperature].

Effects of low ambient temperature (+6 degrees C) on temporal sleep characteristics in cold--acclimated and control rats as well as the interaction between states of animals and energy metabolism levels, were studied. Control rats at low ambient temperature had a lighter, shorter and often interrupted sleep. Cold--acclimated rats slept as much as the control ones at moderate ambient temperature (+19 degrees C) although their sleep, too, was light and intermittent. At both ambient temperatures total and slow--wave sleep was highly correlated with reduction of oxygen consumption in both control and cold--acclimated rats. The maximal decrease of oxygen consumption during sleep as compared with wakefulness occurred in cold--acclimated rats at +6 degrees C. The data obtained are discussed in respect to potential energy connection with sleep.

Adaptation, Physiological↗
PubMed1983

[Changes in thermoregulation in the white mouse treated with endogenous substances from the intestinal tissue of hibernating animals].

Intraperitoneal administration of extracts of the small intestine epithelium of hibernating ground squirrels (C. Parryi Rich., C. undulatus) to white mice caused a decrease in oxygen consumption by 50-80%, the 5.5-14.0 degrees C drop in body temperature, inhibition of the muscle shivering thermogenesis, a decrease in heart rate, reduction of locomotor activity, development of hypnogenic effect and a closer dependence of body temperature on environmental fluctuations. The effects lasted for 30-40 hrs. Extracts from the small intestine tissue of non-hibernating ground squirrels caused insignificant changes of these parameters.

Animals↗
PubMed1980

[Changes in the adrenergic regulation of thermogenesis during prolonged rat adaptation to cold].

Comparison of effects of catecholamines (noradrenaline, adrenaline, and isopropyl-noradrenaline) on oxygen consumption and body temperature and study of influence of beta- and alpha-adrenergic blocking agents (poropranolol and phentolamine) on their calorigenic effects in cold- and warm-adapted rats revealed that affinity of propranolol and all the catecholamines to beta-adrenoreceptors is enhanced. Influence of propranolol on the cold thermogenesis involves thermoregulatory metabolism decrease in warm-adapted rats and additional (compensatory) increase of thermoregulatory electrical muscle activity in cold-adapted rats. The sympathetic regulation of heat production and its changes at prolonged cold adaptation seem to be mainly of beta-adrenergic nature.

Acclimatization↗
PubMed1979

[Changes in muscular thermogenesis in cold adapted rats following beta-adrenoreceptor blockade].

The administration of beta-adrenergic blocking agent propranolol to cold adapted rats entailed some decrease of the total metabolic reaction and body temperature as well as an additive (compensatory) increase of electrical muscle activity. The compensatory effect was more obvious in postural-tonic groups of muscles (m. trapezius, m. masseter) and in deeper portions of muscles (m. tibialis ant., m. trapezius), mainly presented by the red fibers. An adaptive increase of non-shivering thermogenesis and temperature effect of muscular contraction seem to be mainly controlled by beta-adrenergic mechanisms.

Adaptation, Physiological↗
PubMed1979

[Adrenergic regulation of thermogenesis in Siberian lemmings].

Siberian lemmings seem to have lesser noradrenaline (NA) calorigenic action and higher beta-adrenergic "asymmetry" of catecholamine calorigenic effects than the cold- and warmth-adapted laboratory rodents. Selective inhibition of catecholamine effects by beta-adrenoblocking drug propranolol, obvious potentiation of NA effect by caffeine, and compensatory increasing of thermoregulatory musclar contractile activity during the blockade of betaadrenoreceptors under cooling suggest the domineering of betaadrenergic mechanisms of thermogenesis in siberian lemmings and their high thermoregulatory lability.

Animals↗
PubMedDate not supplied

[Changes in thermoregulation, sleep and the thyroid hormone concentration of the blood in the "critical" period of the entry into hibernation of the suslik Citellus parryi].

During the first entering into hibernation in the ground squirrels there are periodic cessations of the process, especially during the transition to moderate and deep torpidity ("critical" periods) which significantly increase energy expenditure in animals during the phase of entering. During this period, high amplitude near-the-hour fluctuations are observed in total duration of wakefulness and sleep, contractile muscle activity, oxygen consumption, heart rate, brain temperature, and thyroid hormone concentration in the blood; at the end of this period, as well as during the exiting from it the duration of deep slow wave sleep significantly increases, paradoxical sleep is not identified. The data obtained confirm a hypothesis of "kindling" homeostasis as neuro-hormonal mechanism of the increase in thermal range of the activity of functional systems of the organism during the entering into torpidity in homoiothermic animals.

Animals↗