Izvestiia Akademii nauk SSSR. Seriia biologicheskaia最新文献

After combined exposures to hypokinesia and radiation, hybrid CBA x C57BL mice of the first generation showed a drop in their working capacity as estimated by the rate of swimming through a limited distance. It was found that hypokinesia was a sufficiently strong stressor, no less affecting the working capacity than ionizing radiation in LD50. There was no summation in effects of these irritants with respect to the drop in working capacity.

A hypothesis is suggested on the positive effect of light radiation on the formation of protective immune mechanism related to the photophysiological destruction of porphyrins. References to experimental data are given which illustrate the possibility for existence of such a mechanism.

The mechanism of effect of plasmin hydrolysis degradation products, fragments DL and DH, on fibrinolysis and fibrinogenolysis processes was investigated on the basis of their various structural and functional characteristics. Using electrophoresis of unreduced samples and degradation products concentrations changing kinetics, DH was shown to be the only fragment which possessed an antifibrinolytic effect. Rauleigh's light scattering analysis indicated the ability of fragments DL and DH to co-form with plasminogen reversible equimolar complexes.

Stimulatory effect of metalloatrans on the development of stomach wall connective tissue components was examined in rats with experimental acetate ulcer. Metalloatrans were shown to inhibit peroxide oxidation processes of lipids in blood and stomach tissue.

Postnatal ontogenesis of hormonal system of hypophysis - adrenal glands and hormonal reaction under stress conditions were examined in adult water mouse, which had polymorphic fur color genes. Black females (genotype aa), opposite to brown ones, (genotype AA, Aa) had changed postnatal ontogenesis of adrenal glands function and they had not hormonal reaction to the two days water deprivation.

Effect of benzimidazole-derivatives on the DNA-protein binding formation was studied after UV-radiation of chromatin. These derivatives were shown to protect chromatin from UV-induced DNA-protein binding formation. Structural analog contained two aminomethyl residuals sensibilized additional binding formation in chromatin. Results suggested, that benzimidazole interacted with DNA, while aminomethyl groups interacted with protein and sensibilized binding of DNA with histone H1.

Kinetics of growth-inhibiting and cytogenetic effect of a new carbon-substituted nitrosourea derivative (ADEKO) has been studied in a wide dose range. A linear dose-effect dependence was observed. The level of damaged cells in a population is connected with a number of chromosomal aberrations per cells with a semilogarithmic dependence. The drug has a pronounced clastogenic effect that reveals itself in total damaging of chromosomal structure of tumor cells. It also causes cell polyploidization with the increase in does and duration of action. Chromosomal aberrations induced by the drug are observed in the tumor long after the action of the drug and their level correlates positively with antitumor activity of ADEKO. ADEKO damages preferentially tumor cells as compared to bone marrow.

Three types of skin glands, the derivatives of the outer root sheath of the hair follicle, have been compared, which are represented by hepatoid, sebaceous and apocrine sweat glands. There are three characteristic properties inherent to hepatoid glands, existence of a network of intercellular secretory tubules, lysis of some secretory cells during the duct formation which is not the fatty transformation and cyst formation.

Thyroid hormone concentrations in blood were elevated all through the hibernating season while thyroid gland showed morphological signs of high activity. The specificities of lipid metabolism, increased fatty acid unsaturation and reduced cholesterol/phospholipids molar ratio in plasma membranes were attributed to high thyroid activity.

The site of action of the goY mutant gene was determined in the aggregation chimaeras C57BL-goY/goY----DBA (+/+). Chimerism was detected by mosaicism of coat pigmentation and electrophoretic pattern of glucose phosphate isomerase. In 28-day-old chimaeras the regions of light-brown coat alternated black coat, stripes of short hairs alternated those of long hairs. These stripes of different length and width extended from spine in lateral-ventral direction. The hairs plucked from long hairs stripes had a similar length that those of goY/goY mice of same age, but the hairs plucked from short hair stripes corresponded to the hair length of +/+ mice. These data show that the goY gene acts in epidermal cells of hair follicles and its expression is autonomous. It has been established that in double homozygotes goY/goYfzY/fzY both mutant genes are expressed: the considerable increase of hair length as compared to norm--the effect of the goY gene and curly coat--the effect of the fzY gene. In goY/goYfzY/fzY mice during the formation of G1 guard hairs the incomplete expression of the goY gene is observed that is due to the suppression of hair growth by the fzY mutant gene. The fzY gene does not suppress the growth of G2 hairs and therefore the full expression of the goY gene occurs in goY/goYfzY/fzY adult mice.