Distribution of alpha 2M-globulin and Lpm-protein in the organs and tissues of the American mink

Distribution in the organs and tissues of two proteins of alpha-macroglobulin fraction, that differ in their antigenic structures, has been studied in the American mink. The both proteins (alpha 2M and Lpm) are present in hepatocytes, in cells of the follicular epithelium of the ovary, in the thymic bodies, in the alveolar macrophages of the lungs and in the splenic lymphoid nodes. Joint localization of alpha 2M and Lpm is revealed in the connective tissue of all the organs examined. The exception make the stomach and the uterine, where alpha 2M is revealed but not Lpm. The results obtained demonstrate a similar distribution of the two alpha-macroglobulins in the mink organism. They correspond to the literature data on morphofunctional topography of alpha 2M in the man. Certain individual differences in alpha 2M and Lpm localization can reflect peculiarities inherent in each of these alpha-macroglobulins of the American mink.     

Determination of penicillinase and acylase by chromatography on a thin layer of sorbent in the case of their joint formation by different strains]

The products of penicillinase and acylase hydrolysis of benzylpenicillin were studied with a method of sorbent thin-layer chromatography. The method provided qualitative determination and differentiation of penicillinase and acylase activity in cultures of E. coli capable of simultaneous production of both enzymes. It was shown that when the cultures of E. coli were grown under conditions optimal for acylase production, the amounts of penicillinase were insignificant.     

Genetico-neurochemical analysis of the role of brain catecholamines in population hierarchy in male laboratory mice

Comparative genetic analysis of social dominance in micropopulations of male mice as well as noradrenaline and dopamine levels in brain was carried out. The RT male mice had maximal level of social dominance and the greatest content of brain catecholamines. It is suggested that the capacity for social dominance may depend on the function of the central catecholamine neurons. This suggestion has been confirmed by the data obtained both for interstrain and intrastrain relations between social dominance and catecholamine levels.     

Changes in the activity of the taste receptor apparatus and the preference for a sodium chloride solution in newborn rats receiving capsaicin]

Taste receptor organ activity and preference of sodium chloride solution in rats with deficit of substance P (SP) were studied. Total impulse activity of chorda tympani nerve of 7-8 week old rats was recorded under nembutal anesthesia. The taste responses to four solutions (sucrose, quinine sulfate, sodium chloride and citric acid) were decreased in rats injected with capsaicin in comparison with rats injected with vehicle. The rats injected with capsaicin preferred water to sodium chloride (two-bottle technique). On the contrary the rats injected with capsaicin preferred the salt solution. These data together with previous studies show the important role of peptide SP in taste receptor activity and "salt appetite".     

Mitochondrial DNA evolution in the genus Equus

Employing mitochondrial DNA (mtDNA) restriction-endonuclease maps as the basis of comparison, we have investigated the evolutionary affinities of the seven species generally recognized as the genus Equus. Individual species' cleavage maps contained an average of 60 cleavage sites for 16 enzymes, of which 29 were invariant for all species. Based on an average divergence rate of 2%/Myr, the variation between species supports a divergence of extant lineages from a common ancestor approximately 3.9 Myr before the present. Comparisons of cleavage maps between Equus przewalskii (Mongolian wild horse) and E. caballus (domestic horse) yielded estimates of nucleotide sequence divergence ranging from 0.27% to 0.41%. This range was due to intraspecific variation, which was noted only for E. caballus. For pairwise comparisons within this family, estimates of sequence divergence ranged from 0% (E. hemionus onager vs. E. h. kulan) to 7.8% (E. przewalskii vs. E. h. onager). Trees constructed according to the parsimony principle, on the basis of 31 phylogenetically informative restriction sites, indicate that the three extant zebra species represent a monophyletic group with E. grevyi and E. burchelli antiquorum diverging most recently. The phylogenetic relationships of E. africanus and E. hemionus remain enigmatic on the basis of the mtDNA analysis, although a recent divergence is unsupported.      

Connection of HindIII-polymorphism in the lipoprotein lipase gene with myocardial infarct and life span in elderly ischemic heart disease patients

Allele and genotype frequencies of the HindIII polymorphism of the lipoprotein lipase (LPL) gene were studied in patients with myocardial infarction (MI) and stable angina of effort (SAE), including long-lived people (over 90). The polymorphism proved to be associated with MI and with the life span, genotype H+/H+ being predisposing to MI and allele H- being protective. The allele and genotype frequencies of long-lived people differed significantly from the Hardy-Weinberg proportions and from those of SAE patients aged up to 90. An excess of heterozygotes in this group suggests a selective pressure which eliminates homozygotes. Possibly, heterozygotes H+/H- have an adaptive advantage, which provides for their longevity.     

Growth,reproductive function,and tolerance to load tests in rats under repetitive adverse conditions

Wistar rats were subjected to a 3.5-day water deprivation once a month in the period of 1 to 10 months of age. The rats' adaptive abilities proved sufficient for compensation of adverse effects, the rats preserved their normal motor activity, emotionality, and orienting behaviour in the intervals between the effects. In the reproductive period, the males manifested a normal sexual behaviour and fertilizing capacity of their spermatozoids. In the end of the experiment, the experimental animals did not differ from the control animals.