[Development of a basic ration out of commercial foods for nutrition in ground-based simulation experiments].

Food rations composed of canned products were given the physiological and hygienic evaluation in the context of their fitness for human volunteers in experiments with head-down bedrest in isolation and confinement. As a result, the food rations were proven to contain the desired quantities of nutrients. Evaluation of food fitness for human subjects was made based on the data of clinical-physiological and biochemical investigations. The rations met the energy and anabolic metabolism demands of human subjects during extreme chamber experiments and were favorable to maintaining good level of vital processes.

[Nutrition of crews of long-term missions on the International Space Station]. / Pitanie ékipazhei dlitel'nykh ékspeditsii na Mezhdunarodnoi kosmicheskoi stantsii.

The integrated Russian-US rations consumed by seven crews of the ISS long-term missions were subjected to hygienic and sufficiency evaluation. The rations were found to contain the necessary quantities of all nutrients. As concluded from the analysis of anthropometrical, physiological and biochemical investigations performed in flight, they supported crew energy and plasticity needs and were a contributing factor in the high level of performance.

[Development of special food products for cosmonaut's nutrition during extravehicular activities]. / Razrabotka spetsial'nykh naborov productov dlia pitaniia kosmonavtov pri vnekorabel'noi deiatel'nosti.

On the analysis of the factual energy expenditure by cosmonauts during extravehicular activities two choices of special rations (SR) were developed. Hygienic testing showed that all nutritional components in these SRs were present in optimal quantities. Consumption of the SR foods during any basic meal will not misbalance the latter but satisfy the body demand of the main indispensable nutritional factors.

[Action of cadmium on the elemental composition and cellular morphology of the hepatopancreas, kidneys and gonads of the mussel Mytilus edulis and scallop Mizuhopecten yessoensis]. / Deistvie kadmiia na élementnyi sostav i morfologiiu kletok gepatopankreasa, pochek i gonady midii Mytilus edulis i grebeshka Mizuhopecten yessoensis.

Studies have been made on the content and distribution of Cd, K, Mg, Ca, S and P in organs and cells of mussels and scallops before and after immersion in water containing cadmium chloride. In normal molluscs, the lowest content of Cd was found in the gonads; cadmium content of the hepatopancreas and kidney in the scallop is correspondingly 20 and 40 times higher than in the mussel. After immersion in water with cadmium (250 micrograms/l in summer experiments and 500 micrograms/l in spring ones), cadmium content of the hepatopancreas and kidney of the scallop was found to be also higher than that in the mussel, although the difference is less significant, being dependent on the season of year. The highest accumulation of cadmium (9.760 +/- 790 micrograms/g dry weight) was observed in the scallop kidney in summer period. After immersion in cadmium-containing water, the content of sulphur in the kidney and hepatopancreas increases, positive correlation being observed between the distribution of Cd and S. Exposure to cadmium results in the increase of Ca and Mg content in the gonads of scallops, as well as in the increase in Ca content of the gonads of mussels. Accumulation of cadmium in the gonads is rather small, maximum density of the material being observed histochemically in the gonadal wall. Morphological changes in the gonadal cells of mussels in summer period may be associated with the increase in cellular calcium.

[Cadmium distribution in tissues and Na,K-ATPase activity of the skin of the frog Rana temporaria in different routes of cadmium uptake by the body]. / Raspredelenie kadmiia v tkaniakh i Na,K-ATFaznaia aktivnost' v kozhe liagushki Rana temporaria pri razlichnykh putiakh postupleniia kadmiia v organizm.

Accumulation, distribution of Cd in tissues and its toxic effect depend of the mode of uptake of Cd by the organism. Subcutaneous injections of Cd (0.12-0.24 mg/100 g per day) for 10 days resulted in a significant accumulation of Cd in the liver and kidney. No death cases were observed. Addition of CdCl2 to the aquatic environment (more than 0.002%) caused acute toxic effect on frogs. Within 10 days, significant amounts of Cd were found in the skin, especially in its outside layers, small amounts were found in the kidney and liver. High external concentrations of CdCl2 (0.005%) inhibited the activity of Na,K-ATPase in the skin epithelium. It is suggested that adaptive detoxication of cadmium in the liver and kidney operating in mammals, is ineffective in amphibians provided cadmium uptake occurs via the skin.

[Effect of lithium on water-salt metabolism in the frog Rana temporaria]. / Vliianie litiia na vodno-solevoi obmen u liagushek Rana temporaria.

Frogs kept in distilled water with 1 mM LiCl loose Na more readily than control animals in pure distilled water. After 10 days of staying in a medium with LiCl, a decrease of total content of Na and K in the body and skeletal muscles was observed together with a decrease in sodium content of the blood serum and intracellular concentration of potassium in muscles. There was no difference in the volume of extracellular fluid between the two groups of frogs. Concentration of Li in the blood serum was 5 times higher than that in the external medium, indicating active transport of Li across the skin. In skeletal muscle fibers, Li concentration was twice lower than in the blood serum. In frogs kept in LiCl solution, the increase in diuresis, as well as the increase in urinary excretion of Na and K were observed. It is suggested that Li ions inhibit sodium transport or prevent hormonal effects on the kidney, urinary bladder and skin of the frogs.

[The effect of lithium on the tissue levels of electrolytes and hyaluronic acid levels in the kidney papilla in the rat]. / Vliianie litiia na soderzhanie élektrolitov v tkaniakh i gialuronovoi kisloty v pochechnom sosochke krys.

Injections of 0.2 M LiCl i. p. (1 ml/100 g/day) induced polydipsia in rats drinking tap water. The plasma lithium concentration and its content in the erythrocytes, skeletal muscles, renal tissue were significantly higher in the rats drinking tap water as compared with rats drinking saline. No significant differences in the body volume of extracellular fluid, muscle water, Na, K content and their muscle intracellular concentrations were noted between the "lithium" and the control rats. Na content in the plasma and the renal cortex--medullar Na gradient were decreased in the "lithium" rats drinking tap water. The hyaluronic acid content in renal papilla was increased in all rats receiving lithium injections. After an injection of ADH the papillary hyaluronic acid content markedly decreased in control rats while it decreased only insignificantly in "lithium" rats. The impairment of the ability of urine concentrating and polyuria in "lithium" rats seems to be partly connected with an enhancement of the polymerization degree of renal papillar hyaluronic acid.

[Effect of lithium on the renal excretory function and Na, K-ATPase activity in rats]. / Vliianie litiia na ékskretornuiu funktsiiu i Na, K--ATFaznuiu aktivnost' v pochkakh krys.

Single administration per os of the 0.066 M LiCl solution (3 ml per 100 g body weight) caused natriuresis. In the "lithium" rats with prolonged lithium treatment (i.p. injections during 10 days), polyuria developed; after water or 0.9% NaCl load excretion of Na, K, Ca, Mg and water increased as compared to the control rats. The saluretic effect was very obvious after 0.9% NaCl load in the "lithium" rats. The Na, K ATPase activity was measured by the quantitative cytochemical method, decreased only in the collecting ducts of the "lithium" rats. The natriuretic effect of acute lithium administration seems to be due to a lowering of the sodium proximal reabsorption. Prolonged lithium treatment suppresses the sodium transport in the collecting ducts.

[Concentration of water, sodium, and potassium in the tissues of rats with circulatory insufficiency caused by constriction of the thoracic portion of the inferior vena cava]. / Soderzhanie vody, natriia i kaliia v tkaniakh krys a nedostatochnost'iu krovoobrashcheniia, vyzvannoi suzheniem gradnogo otdela nizhnei poloi veny.

In edematous rats with circulatory insufficiency, the content of water and sodium in the muscle and liver rises while that of potassium declines per 1 g wet weight. The increased sodium and decreased potassium content in the tissues cannot be accounted for only by enlargement of the extracellular volume. In contrast to normal rats, the edematous ones show a negative linear correlation between the content of sodium and potassium in the muscle and liver. The total content of sodium and potassium in the tissues increases. It is assumed that part of intracellular potassium in the test tissues of rats with circulatory insufficiency is replaced by sodium. The proportion of sodium bound to structural components of the cell increases.

[Kidney function and Na+-K+-ATPase and succinate dehydrogenase activity in the cells of the renal tubules of rats with constriction of the thoracic portion of the vena cava inferior]. / Funktsiia pochek i aktivnost' Na+-K+-ATF-azy i suktsinatdegidrogenazy v kletkakh pochechnykh kanal'tsev krys s suzheniem grudnogo otdela nizhnei poloi veny.

Circulatory insufficiency in rats was induced by constriction of the thoracic portion of vena cava inferior. Two-three days after the operation renal function was studied and the activity of succinate dehydrogenase and Na+K+-ATPase in the cells of the renal tubules was determined cytochemically. On infusion of 0.9% NaCl solution into the stomach, the filtration in the "caval" rats did not change whereas the excretion of sodium and its concentration in the urine were much lower than in the sham operated rats. At the same time, the activity of Na+K+-ATPase and succinate dehydrogenase in the "caval" rats increased in the cells of the proximal tubule, diminished in Henle's loop, and remained unchanged in the cells of the distal convoluted tubule. Comparison of the results of functional and cytochemical study of the kidneys in caval rats allows the conclusion that intensified proximal reabsorption may be the main cause of antinatriuresis in these animals. The lesser load experienced by the distal segment promotes fuller reabsorption of sodium in this part of the nephron too.

[Circulatory insufficiency and edema in experimental constriction of the thoracic segment of the vena cava inferior]. / Nedostatochnost' krovoobrashcheniia i oteki pri suzhenii grudnogo otdela nizhnei poloi veny v eksperimente.

A method for reproducing circulatory insufficiency in rats by constriction of the intra thoracic portion of vena cava inferior is described. A sham operation on the control animals was restricted to thoracotomy. Rats which had been subjected to constriction of the vena cava consumed 0.85% sodium chloride solution intensively under conditions of free choice. This lead to rapid increase in mass with the development of subcutaneous edema, hydrothorax, and ascites within two to three days after the operation. Thinned out muscle fibres with decreased SDH activity were found in the myocardium of the both ventricles. Study of THO, 22Na, 36Cl, and thiocyanate distribution spaces showed that the total body water increase was consequent upon growth of the extracellular space with a constant intracellular volume.

[Distribution of water between the extracellular and intracellular space in rats]. / Raspredelenie vody mezhdu vnekletochnym i vnutrikletochnym prostranstvom u krys.

In anesthetized rats the renal pedicules were clamped and the solution with THO, antipyrine, thyocyanate, inulin, 22Na, 36Cl, 82Br was injected into the tail artery. The space of distribution of THO was 65.1% body weight, antipyrine--81.9%. The volumes of distribution of 22Na (27.4%) and thyocyanate (26.9%) were higher than the 36Cl (24.8%) and 82Br (25.6%) spaces. Inulin space was 13.8%. There was no difference between the volume of distribution of the substances in female and male rats. The same spaces of the substances (except inulin) were determined in rats with intact kidneys. After i.a. administration of 5 ml/100 g body weight of Ringer's solution the recovery of all the substances was about 100%. The data obtained indicate that antipyrine cannot be used for estimation of the total body water in rats. For the measurement of extracellular fluid it is better to use radioisotopes 82Br, 36Cl or 22Na; more variable data were observed with thyocyanate and inulin.

[The ionic composition of different zones of the rat kidney following magnesium chloride administration]. / Ionnyi sostav razlichnykh zon pochki krys pri vvedenii khloristogo magniia.

In 20 min after administration of 0.2 ml/100 g MgCl2 5% solution, Mg contents in the rat kidneys papilla increases while Na and K contents decreases. Administration of 0.2 ml/100 gNaCl 4.4% solution decreases all three ions contents because of enhanced amount of the tissue water. Increase in the Mg content in the kidney tissue is correlated with its content in the blood plasma and not correlated with the changes of its concentration in urine. Increase of the Mg intracellular concentration may be one of the reasons of its reduced reabsorbtion from the tubular fluid.