Eksperimentalna meditsina i morfologiia最新文献

The content of GABA in the following regions of the brain: cerebellum, left and right hemisphere was studied on white male rats. The determination was made by the method of Sutton and Simmonds (1974). One control and 7 experimental groups were investigated. All examined substances were administered intraperitoneally and the animals were decapitated at their peak activity. The effect of newly synthesized hydroxyl amine barbiturate HB-7, administered in several doses, was studied, comparing it with the action of pentobarbital (PB) and of phenobarbital (PB). A considerable increase in the content of barbiturates was established in the cerebellum of rats under the influence of the applied barbiturates while the content of GABA in both large hemispheres was less affected by the administered compounds. A conclusion is made that a single administration of barbiturates affects the content of GABA in some cerebral structures of the rat.

The author carried out a study on the ultrastructure of germinal and Sertoli's column in sexual immature tests of 21 rats of Wistar strain, examined dynamically into the following age groups: newborns on the fifth and tenth days after delivery. After analysing the obtained results the following conclusion could be made: The lack of specific cellular sign of gonocyte to differential A-spermatogonia was a serious obstacle in the study of prepubertal development of male gametogenesis. Examining the differentiation of cellular populations in sexual immature testes of rats, the dynamic of proliferation and ultrastructural changes in the germinative Sertoli's cells, which transformed gradually into their specific structure of sexual mature tests, was impressive. Although the rather difficult determination of factors, coordinating interrelationships between these cells, should be taken into consideration, it is clear that the development of germinal cells could be described always in close connection with the surrounding Sertoli's cells, which play probably a basic role in initiation of their proliferation and entry in miosis.

Distribution of alpha-D-mannose and alpha-D-glucose residues of glycoconjugates in axons of sciatic nerves of 24-month old rats of Wistar strains was studied by concanavalin-A-ferritin conjugate. In some of axons there were cumulations of ferritin molecules in agglomerates of various size with polarization of the phenomenon at preserved integrity of myelin sheath. In other cases the concentration of a large number of lectin binding sites was established in the region of the degenerating part of myelin sheath, engrossed in the axon cylinder. The changes in the distribution of carbohydrate residues in the axoplasm of some of the fibers are discussed in connection with the occurring axonal atrophy in fibers of peripheral nerves of old rats.

Studies were carried out on the influence of bioshik (tinidazol), synthesised and produced by NPSK of Pharmacy at the Medical Academy on reproduction of male and female rats. The experiments were undertaken after oral administration of bioshik in two doses of 100 mg and 300 mg/kg of body mass (1/20 and 1/10 of LD50) at several stages: I stage during natal application, respectively: 1. during sexual maturation and 2. during the period of sexual maturity and II stage during prenatal administration of bioshik. The studies of the second stage were performed on 3-months old male and female rats, a generation of animals, treated with bioshik during pregnancy. The following parameters were determined: sexual receptivity, reproduction, percentage of early resorptions and mean number of normally implanted fetuses. The described data showed that there was inhibition of sexual receptivity as well as of reproduction after usage of higher doses of 300 mg/kg of body mass only natally and more manifested after application during sexual maturation. There were no data on impairement of the examined parameters for reproduction in offsprings after treatment of pregnant rats with bioshik.

Experiments were carried out on male white rats of Wistar strain, placed in metabolic cages in a room with artificial light and dark at 12-hour periods. Furosemide in a dose of 4 mg/kg was used intraperitoneally singly or after pretreatment with methoxamine in a dose of micrograms/kg or prazosin in a dose of 0.2 mg/kg. The renal excretory function was examined for a period of 2 hours. It was established that methoxamine usage increased diuresis without changing substantially sodium, potassium and total osmotic excretion. The application of furosemide after pretreatment with prazosin causes enhanced diuretic, sodium and chloruretic effect without potentiating potassium excretion. Separate examination of nephron functions by lithium clearance and its derivatives shows that alpha-adrenergic blockade reduces both proximal and distal resorption of water and sodium. The interaction of alpha-adrenergic agonist and alpha-adrenergic blocker affects chlorine excretion electively. After application of methoxamine the chloruresis, induced by furosemide, diminishes, but after prazosin pretreatment is increased.

The morphological peculiarities and distribution of thymus eosinophils of 69 conventional Swiss mice in different stages of their prenatal and postnatal development have been investigated. Single granulocytes, located mainly in the cortical zone between the epithelial cells and lymphocytes have been observed. The early appearance of these cells (in 17-18 days old fetuses) and the simultaneous presence of mature eosinophils as well as of their precursors have been discussed with regard to the possibility for the mouse thymus to participate in the eosinophilopoiesis.

The early influence of isoniazide, used by a stomach-tube single or in combination with lipovitane, was studied on some components of electron-transporting chains in the microsomal fraction from livers of male and female rats. In comparatively unchanged amount of cytochrom P450, anilinhydroxylasic activity was increased many times in all experimental groups. This could be explained by induction of the specific isoenzyme of cytochrom P450 by isoniazide. The combination of isoniazide with lipovitane in male rats did not change the additional activity of the enzyme, but it was altered in the female rats in various directions. Isoniazide alone or with lipovitane did not change significantly N-demethylation of aminopyrine. The amount of cytochrom b5 was the same after action with isoniazide. Its combination with lipovitane in male rats reduced significantly the amount of cytochrom b5. Similar tendency in female animals was observed after usage of isoniazide during a longer interval. The reduction of cytochrom b5 was explained by a lowered inclination to lipid peroxidation due to synthesis of phosphatidylcholin, induced by lipotropic components of lipovitane. The applied doses of isoniazide were not hepatotoxic, because triacylglycerols in the serum and liver homogenate as well as nonesterified fatty acids, bilirubin and transaminase activity in serum were unchanged.

The curve of a reduction in plasma concentration of the indicator substance creatinine for a period of 120 to 240 min was investigated after single intravenous administration of creatinine in a dose of 150 mg/kg on dogs. A model for two compartment distribution of the indicator substance was used as the first compartment was intravasal, but the second--interstitial space of body fluids. The following parameters were estimated: renal clearance, volume of distribution, glomerular filtration, intercompartment clearance and velocity constants of transport between the two compartments. An increase of the volume of extracellular fluid (ECF) was induced by intravenous infusion of 2% of sodium chloride solution in the amount of 30 ml/kg. A reduction in the volume of ECF was caused by peritoneal dialysis with isotonic solution of glucose in the amount of 5% of the body mass. After an increase of the volume of ECF there was an increase in the volume of distribution, elevation of glomerular filtration and a reduction in the velocity constant of transport from the intravasal to interstitial fluid. There was a reduction in the volume of distribution, limitation of glomerular filtration and increment of velocity constant of the transport. The established changes in the velocity constants of the transport showed changes in the dynamics of body fluids, which could be due to vasoconstriction or vasodilation as a mechanism of myogenic autoregulation during changes in the volume of ECF.