Physiological Features of Perigonadal Adipose Tissue Containing Uncoupling Protein UCP1 in ICR Mice.

Immunoreactive uncoupling protein UCP1 was found in the perigonadal fat of only twothirds of 14-week-old male ICR mice. The presence of UCP1 had no effect on the rate of O2 consumption by the adipose tissue. The cellularity of perigonadal fat estimated by the DNA content was significantly higher in tissue containing UCP1 than in samples without this protein. This regularity was also observed after adaptation of mice to moderate cold (10oC) over 8 weeks.

Can thermogenic adipocytes protect from obesity?

The role of brown adipocytes and adipocytes of a new beige type in the energy metabolism of a healthy person and in the pathogenesis of obesity has extensively been discussed in recent years. The interest to these cells has been stimulated owing to the application of new noninvasive methods for studying the metabolic activity of tissues. Using these methods, the presence of thermogenically active adipocytes in adults and their reactivity to cold stimuli have been proved. These data, together with the results of animal experiments support the idea of thermogenic fat being a direct regulator of the energy balance of man. However, for several reasons there are some objections to this viewpoint. The main objection is that the total activity of the human thermogenic adipocytes is about 100 kJ/day, i.e., it is negligible. In addition, the burn of excessive nutrients is biologically inappropriate for an organism. Therefore, the idea that obesity is caused by the decreased activity of thermogenic adipocytes is erroneous. The statement that the causes of obesity are associated with the increased efficiency of energy-dependent processes seems more reasonable. The consequence is a reduction in energy expenditure to perform a unit of biological work. This results in excess of nutrients deposited in the form of fat.

Effects of Long-Term Food Restriction Under Thermoneutral Conditions on Brown Adipose Tissue of Laboratory Mice.

Long-term food restriction (3 weeks, 60% of normal consumption of control animals) was followed by an increase in DNA and protein content in the intercapsular brown fat of mice. As the animals were kept under thermoneutral conditions, these changes are thought to be a result of food restriction.

Energy metabolism and biochemical features of adipose tissues in ICR mice after long-term calorie-restricted diet.

Long-term calorie-restricted diet (8 weeks, 60% of control food intake) was followed by an increase in thermogenic activity of interscapular brown fat. The relative amount of DNA and protein and the rate of oxygen consumption increased and tissue-specific marker of brown fat (uncoupling protein UCP1) appeared in significantly reduced deep-pink abdominal adipose tissue.

Effect of calorie restricted diet on brown adipose tissue in mice.

Calorie restricted diet (50% food intake of control animals) for 3 weeks decelerated weight gain in laboratory mice, reduced the weight of abdominal fat, and decreased the rate of oxygen consumption by brown adipose tissue. The relative weight of interscapular brown fat and protein content in it did not differ from the control. DNA content in brown fat in mice kept on calorie restricted diet increased by 93% compared with the control.

[Evoked potentials and processing of visually presented Poggendorff figure].

We have been studying association between distorted perception and visual event-related potentials, which appear in response to the Poggendorff figure's presentation in Jastrow modification. It was shown that the amplitude sign is determined by the presence or absence of subjective distortion at the earliest and the latest phase of Poggendorff figure's perception. The amplitude of the wave P150 was bigger at the distorted perception, and the amplitude of the waves N200 and P300 was smaller than during perception without distortion. It is suggested that both ascending nervous processes and cognitive processes of analysis are involved into the emergence of the Poggendorff illusion.

[Age-specific changes in anthropometric values of Krasnoiarsk children]. / Vozrastnaia dinamika antropometricheskikh pokazatelei detskogo naseleniia Krasnoiarska.

The physical development of Krasnoyarsk children was studied. The anthropometric values of children aged 7-16 years were shown to become stable by the mid-1980s. The specific features of today's children versus those of the 1970s is an increase in the nonuniformity of physical development in puberty.

[Brown fat tissue in humans]. / Buraia zhirovaia tkan' cheloveka.

Brown adipose tissue (BAT) is universally present in mammals. Thermal production in such tissue is physiologically important for maintaining temperature homeostasis and regulation of body mass in small-size homoiotherms. At present it is clearly established that unlike other large mammals, brown adipose in man and primates is retained throughout the whole postnatal othogenesis. Therefore, BAT appears as a possible effector of pharmacogenetic protection from human excessive adiposis. Systematic reserach of various functioning aspects of this unique organ of mammals were started abroad as early as 1960-es, and are actively developing at present. Domestic research of energy circulation physiology and of thermoregulation developed mostly outside the brown adipose tissue. Therefore, the principal objective of this publication is to draw attention of experimental and clinical researches to an intriguing aspect of the issue of energy circulation in humans--the issue of brown adipose functioning.

Effect of semi-compulsory alcoholization on brown fat in mice.

We studied brown adipose tissue isolated from mice receiving 20% ethanol as a single source of fluid. In vitro O2 utilization by brown adipose tissue decreased after one month of forced alcohol intake, but surpassed the control after 3 months of ethanol drinking. The absolute and relative weight of brown adipose tissue also increased at this term. The rate of in vivo O2 utilization also decreased during the first experimental month and returned to normal after 3 months.

[The effect of overfeeding the young in early postnatal ontogeny on brown fatty tissue]. / Vliianie perekorma molodniaka v rannem postnatal'nom ontogeneze na buruiu zhirovuiu tkan'.

We studied the effects of overfeeding of neonatal Wistar rats on O2 consumption by the interscapular brown adipose tissue and DNA content in the tissue. The overfeeding was induced by reducing the litter size to two to three pups per dam compared with standard litters of five to ten pups. All animals were allowed free access to water and forage and were kept at 24 +/- 1 degrees C. Newborn and 16-day-old rat pups were used in the experiments. The body weight of overfed pups was significantly higher than that of standard fed pups (p < 0.001). There were no differences between groups of 16-day-old rats in the resting metabolic rate. The mass of dried brown adipose tissue relative to the body mass in overfed pups was lower than in the control pups (p < 0.01). O2 consumption in the rats from small litters was 35% higher (p < 0.001). DNA content (mg/g brown adipose tissue) in overfed rats was 35% lower as compared to the control pups (p < 0.001). These results indicate that overfeeding at the preweaning stage of life affects growth, cellularity, and thermogenic function of brown adipose tissue.

[A comparison of some methods for administering the Ca-dependent photoprotein obelin into the adipocytes of the brown fat in the rat]. / Sravnenie neskol'kikh metodov vvedeniia Ca-zavisimogo fotobelka obelina v adipotsity burogo zhira krysy.

An attempt was taken to incorporate Ca2(+)-dependent photoprotein obelin into young brown adipocytes using the three methods: 1) osmotic lysis of pinocytotic vesicles; 2) electroporation in a high electric field; 3) hypoosmotic shock. The young adipocytes were isolated from rat interscapular brown fat. The maximum incorporation of obelin into these cells was achieved using the hypoosmotic shock technique. A constant luminescence of intact cells loaded with obelin following hypoosmotic shock was observed in three independent experiments.

[The Na+-K+ pump and the thermogenesis of brown fatty tissue]. / Na+-K+-nasos i termogenez buroi zhirovoi tkani.

Mechanisms of participation of Na+K(+)-pump in regulation of the brown adipose tissue are discussed. It is settled that the increase in ATP hydrolysis by Na(+)-K(+)-ATPase is not a dominating factor of thermogenesis activation. It is assumed that the Na(+)-K(+)-pump, through the intracellular K+ concentration, serves a chain relating proliferation and thermogenesis of adipocytes.

[Reduction of the functional activity of the calcium pump of the sarcoplasmic reticulum of skeletal muscles in response to cold]. / Snizhenie funktsional'noi aktivnosti kal'tsievogo nasosa sarkoplazmaticheskogo retikuluma skeletnykh myshts pod vliianiem kholoda.

Fragments of sarcoplasmic reticulum (SR) from the white skeletal muscles of rat in cooling (1.5 day; -9 to +2 degrees C) revealed a decreased activity of the Ca2+-pump and rate of Ca2+ accumulation. The SR from rats adapted to cold for 2 and 4 weeks, revealed the same decreased functional ability. The Ca/ATP ratio was unchanged in all experiments.

[Deposition of potassium and water in the brown adipose tissue of cold-adapted rats]. / Deponirovanie kaliia i vody v buroi zhirovoi tkani u adaptirovannykh k kholodu krys.

The rats adapted to 0-4 degrees C increased water content in the BAT. The Na and K intracellular contents was unaltered during first month of the adaptation. K content in the BAT was considerably increased by the 10th and 18th weeks of the adaptation. A positive correlation between Na and K contents was revealed in the BAT of both adapted and unadapted rats. The increase of K concentration and the decrease of Na/K ratio suggest that, in prolonged adaptation, the Na-pump power grows more than is necessary for compensation of the high fluxes of cations through the cell membranes in the BAT.

[Concentration of potassium and sodium in the white and red muscles of the rat during adaptation to cold]. / Soderzhanie kaliia i natriia v belykh i krasnykh myshtsakh krys pri adaptatsii k kholodu.

The K+ and Na+ contents changes considerably in cold adaptation only in the rat white neck muscles, remaining the same in the red muscles of hind-limbs. The ratio of K+/Na+ intracellular concentration gradually reduced from 19.8 +/- 1.7 prior to the adaptation to 12.6 +/- 1.4 within 9 weeks of the cold adaptation.

[Changes in the concentration of Na+ and K+ in the skeletal muscles of the rat during adaptation to cold]. / Izmenenie soderzhaniia Na+ i K+ v skeletnykh myshtsakh krys pri adaptatsii k kholodu.

Intracellular Na+ concentration was found to increase in skeletal muscles of rats adapted to cold whereas K+ concentration decreased. The data obtained indicate a reduction of Na-pump capacity in skeletal muscles of rats adapting to cold.

[Na+, K+-ATPase activity of the kidneys and 3,5,3'-triiodothyronine levels in rat plasma during adaptation to cold]. / Aktivnost' Na+, K+-ATPazy v pochkakh i uroven' 3,5,3'-triiodtironina v plazme krys pri adaptatsii k kholodu.

No correlation between Na, K-ATPase activity increase in rat kidney and the level of T3 in blood plasma was revealed in course of the rats adaptation to cold. Spironolactone prevented the enzyme activation caused by cold. Actinomycin D, administered to the acclimated rats two days before the experiment, decreased the enzyme activity. Addition of actinomycin D to membrane preparation did not change the enzyme activity. The increase in Na, K-ATPase activity in kidney during adaptation of rats to cold appears to be related to DNA-dependent synthesis of RNA. The enzyme activation was apparently regulated by aldosterone but it was not the T3-dependent process.

[Activation characteristics of ouabain-sensitive respiration and Na,K-ATPase in the kidney cortex and medullary zone of rats adapted to cold]. / Osoebnnosti aktivatsii uabain-chuvstvitel'nogo dykhaniia i Na,K-ATFazy v kore i mozgovoi zone pochek krys, adaptirovannykh k kholodu.

The endogenous and ouabain-sensitive respiration and Na, K-ATPase activity in the cortex and kidneys medulla of the cold-acclimated male albino rats have been determined. The increase of the respiration rate has been stated to be caused by the Na-pump activation. The obtained changes of Na, K-ATPase activity are supposed to be connected with the regulation of concentration and sodium excretion function of kidneys.