Fiziologicheskiĭ zhurnal最新文献

The chronic effect of electrostatic field has been studied in experiments on adult female Wistar rats. It is shown, that under these conditions the stability of erythrocyte membranes decreases, that causes their earlier hemolysis. The level of calcium and iron in blood increases, that is correlated with changes in the urea content. In the brain iron content decreases, while urea increases. The obtained results reflect the active establishment of dynamic equilibrium in conformity with this influence.

Remote effects of neonatal 6-hydroxydopamine (6-OHDA) combined with testosterone propionate (TP) and alone were compared to ultrastructure of catecholaminergic terminals of the median eminence and hypothalamic catecholamine (CA) content in the critical period of sexual differentiation of the brain. It is suggested that inability of 6-OHDA to prevent TP-induced anovulatory sterility is connected with the preserved hypothalamic CA levels and a lack of significant degenerative changes in CA-ergic terminals in the median eminence.

The mechanisms of protective action of Lactobacillus have been studied during development of the generalized infection induced by Klebsiella pneumoniae in CBA mice after weaning. The mice were infected intragastrically during the first day after weaning (1 x 10(9) bacterias per mice). Suspensions of Lactobacillus were introduced before and after infection during 10 days (1 x 10(6) bacterias per mice). It has been shown that introduction of Lactobacillus substantially decreased the level of the gut contamination by Klebsiella, prevented generalization of infection and death of animals. Significant higher levels of IgA in the blood serum, IgA and IgM in the gut content, percentage of splenocytes, expressing surface IgM and IgG were observed on the 7th day as compared with those in animals without Lactobacillus. Significantly lower percentage of splenocytes, expressing CD4 antigen was also observed. On the 11th day after infection the mice receiving lactobacillus have shown a tendency to an increase of IgA in the gut content, significantly lower concentrations of IgM in the gut content and a higher level of IgA to the blood serum as compared with the control. Other characteristics were comparable to those of the control group. A conclusion is made that introduction of Lactobacillus prevents development of the Klebsiella infection and protects the immune system from excessive antigenic action.

The secretory status of mast cells of mesentery and subcutaneous connective tissue was studied in rats using the morphometry analysis. Immobilization for 30 min has induced a 3.7-fold decrease of the heparin saturation index in these mast cells and a 3-fold increase of the granulolysis index. In rats preliminary given propranolol, alpha-adrenoceptor antagonist (1.25 mg/kg), a stimulatory effect of immobilization was absent. Phentolamine, alpha-adrenoceptor antagonist (6 mg/kg), partially inhibited the immobilization effect. Isoprenaline, beta-agonist (1.5 mg/kg), activated heparin secretion in rats without immobilization, while phenylephrine, alpha-agonist (2.5 mg/kg) had no effect on the secretory state of mast cells. Propranolol in the same dose also blocked the stimulatory action of i. v. injected alpha-thrombin (50 NIH/kg) on heparin secretion from mast cells of subcutaneous connective tissue. The obtained results show that catecholamines participate in activation of heparin release from mast cells induced both by the stress and by thrombin injection. Their action is mediated by beta-adrenoceptors of the vessel wall.

Changes in concentration of the rat blood serum malone dialdehyde (MDA) at separate and combined action of ethanol and acetaldehyde under conditions of their single and long-term administration have been investigated. In some series of experiments acetaldehyde and ethanol were administered together with teturame. The obtained data permit supposing that under conditions of acute ethanol intoxication an increase of the MDA concentration is caused by the acetaldehyde action. The long-term ethanol intoxication induces a significantly higher (if compared with acute intoxication) increase the MDA concentration. The results confirm the concept of the lipid peroxidation process at acute and chronic intoxication due to ethanol metabolism. Acetaldehyde is an important factor among those determining disturbances of cell biogenesis in the animal organism, causing an increase of the blood serum MDA.

Distribution of the total radioactive label in the blood, different parts of the brain (the whole cortex and its lobes, bulbi olfactorii, hippocamp, striopallidum, hypothalamus, thalamus, peduculi cerebri, cerebellum, pons, medulla oblongata), eye (retina, hyaloid and vascular membrane), hypophysis and liver of guinea pig males has been studied after the hypodermic injection of [14C] GABA and products of its conjugation with pyridoxal phosphate, nicotinic acid and biotin in the equimolar dose (50 nmol/g) under normal conditions and in case of action of the closed volume factors. Accumulation of the total label in the hypophysis after injection of [14C] GABA, PLP-[14C] GABA and nicotinoyl-[14C] GABA was 3.6, 3.1 and 2.7 times (respectively) as much as that in the blood. The content of the labelled compounds in the cortical structures of the telencephalon and in the diencephalon was the greatest in comparison with other parts of the brain. The permeability through a hemato-ophthalmic barrier was 3-5 times as much as that through a hemato-encephalic barrier. The closed volume factors lead to higher accumulation of the label as compared with the control after injection of [14C] GABA, PLP-[14C] GABA and biotinyl-[14C] GABA.

The experiments were performed on the sciatic nerve of Rana temporaria. A single rectangular electric impulse and a series of rectangular microsecond impulses were used for stimulation. The threshold amplitude of a single impulse and the average voltage in series of impulses were compared. It was experimentally shown that application of a series of impulses as a stimulus necessitated less values of stimulation near the threshold. There was no significant difference between the average voltage in a series of impulses and the amplitude of a single rectangular impulse in stimulation far up the threshold.

Embryonal (calf) and ordinary (cattle) blood sera have ben studied experimentally on a primary culture of thyroid cells from newborn pigs for their effect on basal and thyrotropin (TSH)-stimulated 131I uptake by thyrocytes. It is shown that the value of this index is inversely proportional to the relative percentage of the blood serum in the cultivation medium. The concentrations being equal, the ordinary blood serum effect is more pronounced than the embryonic one. Thyrocyte incubation in a medium with 1% blood serum and 0.1-10.0 mU/ml TSH stimulates 131I uptake by the cells, whereas 15% concentration of the blood serum blocks the influence of this hormone. Ouabain (0.1 mM) and cyclohexamide (10 micrograms/ml) have also an inhibiting effect on exposure of the basal and TSH-stimulated uptake of the isotope. It is suggested that the blood serum contains biologically active substances inhibiting the transmembranous transfer of iodides into thyrocytes. This process is controlled by Na+, K(+)-ATPase, and its TSH-stimulation is mediated by protein synthesis de novo.

The quantitative composition of the peripheral blood, enzymatic activity of neutrophils and hypoxic ventilatory drive were determined in people working at the Chernobyl NPP during sojourn for 28 days in the Caucasus mountains at 220 m altitude with a periodical climbing up to 4200 m. At the initial state we found neutropenia, lymphocytosis, an increase in the number of prolymphocytes and big hairy lymphocytes, a decrease in the number of small lymphocytes, fall in activity of enzymes responsible for oxygen-dependent and oxygen-independent mechanisms of bactericidity. The indices of sensitivity to the hypoxic respiration stimulus did not essentially differ from the norm. Staying at altitude promoted normalization of the number of segmento-nuclear neutrophils, lymphocytes (their small population, in particular), an increase in the number of eosinophiles of the peripheral blood. Changes in the activity of myeloperoxidase, NADP-oxidase and cationic proteins in the neutrophils were observed. A considerable increase of the ventilatory drive to the hypoxic respiration stimulus was determined. Accentuation of fermentative transformations proved to be closely related to the ventilatory response to hypoxia: weak activation of NADP-oxidase and a decrease of myeloperoxidase activity were observed in people with initially low respiration reactivity, while a considerable increase in activity of these enzymes and in content of cationic proteins was observed in people with high respiration reactivity. Individual peculiarities of the reaction to staying at altitude should be taken into account when developing particular methods of immune correction.

In the experiments on rabbits under prolonged hypokinesia the functions of the cardiovascular system and the adrenergic reactivity of blood pressure were studied. The increase of the heart rate at rest, clear tendency to the decrease of the arterial blood pressure and no changes of the venous pressure are shown. The reliable decrease of the maximum size and duration of the blood pressure reactions to adrenaline are demonstrated. These changes prove the decrease of the functional possibilities and adrenergic reactivity of the cardiovascular system under hypokinetic conditions.