Fiziologicheskiĭ zhurnal最新文献

The results of experiments on white rats, consuming different quantities of NaCl, show that excessive sodium chloride load increases osmolarity of blood plasma mainly due to excessive accumulation of Cl- in the blood. At the same time urine osmolarity increases by a factor of 10 due to the rise of water reabsorption and a fall in reabsorption of osmotical active substances such as sodium, potassium, chlorides, phosphates and other ions showing tendency to the glomerulus filtration rate rise. This testifies to the priority of osmoregulation over ionoregulation. NaCl injection causes a fall in difference of Na+ and Cl- concentrations in the blood plasma due to Na+ deposition by tissues, which leads to extracellular metabolic acidosis. Kidneys respond to it by a decrease of the urine pH and increase of excretion of hydrogen ions in the form of titrated acids and ammonium, as well as by removal of chloride ions which are not connected with sodium. The conclusion is made that kidneys' function of acid-excretion depends first of all on the acid-base status of extracellular fluids and not on intracellular pH. Concentration of corticotropin in the blood increases in the case of sodium deficiency as well as in the excess of sodium. Deficiency of Na+ intensifies activity of the renin-angiotensin-aldosterone system and decreases ADH secretion, while salt load produces just the opposite effect. The role of the hormones in kidneys' compensatory reaction to excessive NaCl load is discussed.

In a series of short (up to 45 min without considering time of decompression) dives (SD) at depths down to 100 m under conditions of the Barentsev Sea five professional deep-sea divers were examined. In dives down to 40 m compressed air was used as breathing media, in dives to 60, 80 and 100 m--nitrogen-heliox mixture. Before the SD series the volume and velocity lung variables at rest and during forced expiration in air and heliox media were measured between separate SDs and on the 3rd day after the end of decompression with dive to 100 m, using computer spiro- and pneumotachometry methods. Bronchospastic syndrome, playing the leading role in the development of transient isolated or generalized airway obstruction, was shown to be evoked in divers during conduction of SD series. Obstructive phenomena are presumed to be connected with elastic properties' disturbance of lung tissue and development of expiratory collapse; they might cause continuous lung dilatation.

Endocrine function of thymus estimated by titer of thymic serum factor is inhibited in pubertal mice CBA/Ca under conditions of pharmacological inhibition of epiphysis function by beta-adrenoblocking agent anapriline. After blinding and epithalamine and melatonine introduction the content of thymic hormone considerably increases. Melatonine is characterized by manifestation of effect in earlier periods of research. In mice with hyperfunction of epiphysis mass, cell character of thymus and spleen increase as well as the content of thymosine-like activity in supernatant of cultures of splenocytes. And on the contrary, in animals with hypofunction of epiphysis the values of studied immunological indices decrease. Immunopotentiating effect of epiphysial factors is observed not only in vivo but also in vitro and decreases in thymectomized mice. The change of the concentration of glucocorticoids in the organism is of significance in the mechanism of epiphysis effect on the immune system.

Clinico-neurophysiological study of the functional state of the nervous system was performed for persons who participated in elimination of the Chernobyl accident consequences in 1986, as well as for persons working in the 30 km zone. Mean age of the persons was 41. Vegetative dystonia syndrome was diagnosticated in 50% of examined subjects. The increased perception and pain thresholds, as well as the thresholds' asymmetry were determined in 30% of patients. The conduction velocity of sensory and motor nerves, as well as the neuromuscular transmission were normal. No substantial changes in parameters of the soleus H- and M-responses were detected. A decreased amplitude and increased latency of the evoked skin sympathetic potential were found indicating a decreased tone of the adrenergic sympathetic vasoconstrictors and cholinergic sudomotor fibres, that may be one of the pathogenic mechanisms of the sensory, vegetotrophovascular disorders for these subjects. Decreased activity of the sympathetic autonomic system causes permanent course of the vegetative dystonia syndrome and more seldom the parasympathetic autonomic paroxysms. A decreased tone of the sympathetic autonomic system may be due to the monoaminergic neuromediation inhibition (decreased noradrenaline and dopamine excretion for the same subjects), that can induce psychoemotional disorders, depression and sleep-wakeness cycle disorders.

A new type of reaction to the myocardial ischemia was established in chronic experiments in conscious dogs. It consists in some changes of local myocardial activity and, consequently, in constant or transient normalization of ECG. Pharmacological stabilization of this process augments myocardial resistance to ischemia 40-50 times and more. The role of small doses of pituitrin in this reaction was established.

The review summarizes data about interconnection between atherosclerosis and diabetes mellitus. Special attention is paid to their joint developmental factors such as hyperinsulinemia and insulin resistance. It is shown that hyperinsulinemia may form an independent risk factor. At the same time both factors can lead (during both diabetes mellitus and atherosclerosis) to changes in lipid metabolism and development of atheroms. Mechanisms of the development of insulin resistance and hyperinsulinemia are analyzed. The so-called syndrome X is described in detail. It is characterized by a triad of changes: insulin resistance and hyperinsulinemia, changes in lipid metabolism and hypertension. Some methods of treatment of insulin resistance and hyperinsulinemia during atherosclerosis and diabetes mellitus are described.

A model of experimental nephritis in Wistar rats has been used to show that the pathology mentioned induces sharp morphofunctional changes in the parenchyma of the kidneys. At the same time the state of the T-link (lymphocyte blasttransformation response to phytohemagglutinin) and B-link (a titre of serum antirenal antibodies) of the immunity were studied. It is shown that development of experimental nephritis is accompanied by intensification of the lymphocytic response to phytohemagglutinin and renal tissue antigenes with a simultaneous increase of a titre of antirenal antibodies. To correct these damages a complex of polypeptide substances isolated from the kidney parenchyma was applied. The results obtained demonstrate a normalizing effect of this complex on lymphocyte activity. A conclusion is made on possible tolerogenic action of substances of this complex.

Rabbit antibodies specific to sarcolemma of cardiomyocytes have been studied for their effect on activity of 5'-nucleotidase ecto-enzyme of the Wistar rat cardiomyocytes. It is shown that incubation of isolated plasma membranes of cardiomyocytes of rats (100 micrograms of protein) with the gamma-globulin fraction of antisarcolemmal cardial serum (gamma-ASCS, 20 micrograms protein) and with the gamma-globulin fraction of normal rabbit serum (gamma-NRS, 0.20 micrograms protein) promotes a decrease of the enzyme activity. An inhibiting effect was greatly pronounced in incubation with gamma-NRS and did not depend on the dose of antibodies and duration of their action. An assumption is made that inhibiting action of antibodies on activity of ecto-5'-nucleotidase may change adenosine concentration and may be one of elements in the mechanism promoting an increase of the intracellular calcium concentration.

It is revealed that children 7-9 years old lack a correlation between properties of principal nervous processes and properties of attention. Such connection appears only in age of 9-10. Development of properties of principal nervous processes as well as of attention in early ontogenesis is characterized by their quick growth.

Examinations of energetic metabolism in liver of white rats with acute fluoride intoxication were carried out in acute and recovering periods. The influence of hyperbaric oxygenation on the change of energetic metabolism indices and on survival rates of animals has been studied. Hyperbaric oxygenation greatly prevented profound metabolic disturbances, in particular, ATP, increased detoxic in liver intensifying energetic forming processes. The survival rate of animals under the influence of course of HBO increased by 27% during first 72 hours. It was determined that HBO has an effective influence on the course of recovering period during fluoride intoxication.