Izvestiia Akademii nauk SSSR. Seriia biologicheskaia最新文献

Using the radioimmunological assay, renal cAMP content was studied in adrenalectomized and non-adrenalectomized rats with reflex dystrophy resulting from chronic ischiatic nerve stimulation against the background either of organ denervation or of general beta-adreno-blockade with propranolol. It was shown that the surgical denervation of kidney resulted in an increase in renal cAMP both in norm and especially in reflex dystrophy. The beta-adrenoceptor blockade with propranolol was accompanied by a decrease in renal nucleotide being more pronounced in animals with intact ischiatic nerve. Based on own and literature data we have suggested that one cause for the damage to renal aldosterone receptors in reflex dystrophy under pathological stimulation from the focus of damage in ischiatic nerve as well as for their improved functioning in surgical or pharmacological (beta-adrenoceptor blockade) desympathization which discontinues this stimulation, may be change in cAMP content. Via cAMP-dependent protein kinases, this nucleotide triggers a complex system of intracellular metabolic transformations which is able to change the protein spectrum of cytoplasm, nucleus, and chromatin and, therefore, the protein complex of aldosterone receptors. A participation of other biochemical systems of aldosterone stimulus transmission, including cAMP-independent ones, in processes of damage and normalization of tubule cells of the kidneys undergoing reflex dystrophy cannot be excluded.

It has been found that low molecular heparin (LMH) forms complexes with fibrinogen and thrombin. The formation of the heparin-fibrinogen and heparin-thrombin complexes has been testified by cross-linked electrophoresis. The reaction of complex formation was carried out at variable weight ratios of the components, i.e. 1:3 and 1:6, respectively. This complex causes lysis of unstabilized clots of fibrin. All these complexes manifested a slight anticoagulative activity.

Pre-adaptation of normal and tumor cells to the action of methylnitrosourea was studied. To attain these ends, a single low dose (10 mg/kg) was administered to animals two hours prior to the administration of main therapeutic dose (100 mg/kg) and the number of chromosomal rearrangements was determined. A significant decrease in translocation incidence was observed in metaphases of Ehrlich-ICP ascitic strain. Similar results were obtained on cells of murine bone marrow. The mechanisms of pre-adaptation to the action is discussed.

The effect of cytostatics (methylnitrosourea and methotrexate), immunomodulators (thymalin and reaferon) and their combinations on the mitotic pathology of mice Lewis tumour cells was studied. It was revealed that chemotherapy with these agents changed the interrelation between mitotic phases and somewhat enhanced the incidence of pathologic mitoses mainly connected with the damage of mitotic apparatus. Immunomodulators differently affected the cytostatic activity of antitumour agents that may be associated with their mechanisms of action.

Methods have been developed for the in vivo quantitative estimation of biological activity of angiogenin, a protein growth factor of blood vessels. The quantitative analysis of angiogenin with the methods of angiogenetic disks in isotopic modification requires nanogram amounts of the angiogenetic. The cutireaction test is less sensitive though technically simple. The methods are developed on animal (mouse and rat) tissues.

The intensity of protein synthesis (incorporation/pool) is usually low in normal stomach mucosa and enhanced in exacerbation of peptic ulcer; following the effective laser therapy it decreases only in one third of cases. Therefore the scarring of ulcer not always coincides with the normalization of protein synthesis. The results characterize also the community of reactions in stomach and duodenal mucose membranes. The changes in protein synthesis intensity following the laser irradiation depended neither on the initial size of ulcer nor on the age of patient and the total duration of disease.

The article is devoted to the effect of context on the acoustic activity of bank voles of 4 species (Clethrionomys glareolus, C. centralis, C. rutilus, and C. rufocanus) living in experimental groups. In addition to species differences and social state of a specimen in the group, the acoustic activities of vole is affected by such factors as locomotor activity of the vole itself and its partners (especially dominant ones) and aggression of surrounding voles.

Hypothesis is developed about mechanisms of determination of limb bud of mammals as a result of expression of homeo box containing genes (hox genes) of known up to date four hox families. Spatial pattern of the expression plays a role of coordinate system for subsequent processes of morphogenesis and differentiation of the limbs. Propositions of the hypothesis are realized in a computer dynamic model. The results of modeling are compared with known data on features of the expression of hox genes in the mesenchyme of developing limb buds in mammals and birds.