Bokov D.A., Obidchenko M.P.
MORPHOPHYSIOLOGICAL REGULARITY OF FEMALE PYGMY WOOD MOUSE (SYLVAEMUS URALENSIS PALLAS, 1811) PUBERTY: INTRAOVARIAL FACTORS AND ENVIRONMENTAL CONDITIONS ^{[№ 3 ' 2017]}
Puberty of female pygmy wood mouse, as an ecological phenomenon, is a complex morphophysiological process of forming groups of reproductively active individuals at the population level, and the development of the reproductive system, based on ovaries' organ differentiation. Conditions of animals puberty define functional and reproductive heterogeneity of the elementary populations' structure and the specificity of the active mechanisms of population reproduction adaptation processes. To date, the environmental aspects of female pygmy wood mouse puberty remain to be studied insufficiently. Using population-statistics, histological, morphometric methods we studied the dynamics, volume, direction of ovaries' organ differentiation and functionally-reproductive structure of pygmy wood mouse elementary populations according to fertility level and population density. It was found that in groups with low population density the proportion of females, whose fertility is low (3–5 embryos per individual), increases. It indirectly evidences of earlier puberty. Histological analysis has showed that such animals have ovarian hyperplasia, when just emerged on the surface mice have folliculogenesis and endocrine activity of the gonads. In populations with a high population density up to 70 % of females usually have 6–7 embryos per one. There puberty is blocked. Firstly, there are females with gonadal hypoplasia, when the ovary has featured of embriotipical organ. Secondly, folliculogenesis of some animals is controllable suppressed because of developing glandular structures in ovarian cortex, whose endocrine activity depresses the central influence on the sex glands. Thus, we received information about new mechanisms of reproduction regulation in populations of pygmy wood mouse, based on adaptive control of females puberty.

Bokov D.A., Neverova P.S., Obidchenko M.P., Senchukova M.A., Shevluk N.N.
EXPERIMENTAL MODELING OFTOXIGENIC PATHOLOGYEMBRYOGENESIS: ENVIRONMENTAL ASPECTS ^{[№ 10 ' 2015]}
Using patented models of experimental gastric cancer on the subacute formaldehyde chronic intoxication background, it has been studied its effect on the laboratory rats' pregnancy and development of the embryo and fetus.The results reveal a disorder of the volume and direction of the histological and organ differentiation process that determines the subsequent animals' stillbirth. Particularly, histological examination has found that stillborn rats have fetal and even embryonic organs. Their lungs werein the saccular stage of development. Cuboidal epithelium of saccules was not changed on squamous one. Strom was presented by only cellular elements, its elastic fiber component wasn't expressed.Formation of adequate alveolar-vascular relations was delayed.These structural factors contribute to the inability to maintain an effective gas exchange.The kidneys of these animals were on the metanephrogenicblastema stage.The digestive tube was at the epithelial plug stage.In the skeleton there were no centers of ossification.The whole complex morphogenetic phenomena allows to prove unviability of newborn rats: a significant proportion of their stillbirths.At the same time, fertility, the possibility of pregnancy and its parameters are suppressed, that resulting in a decrease in weight and number of newborn rats. Long-term intake of subthreshold concentrations of formaldehyde, caused by the accumulation of the substance in hydro- and edafosfere, proves embriotoxic value of xenobiotic and poor prognosis of pregnancy and the end of gestation, considering carcinogenic effects and cancer of the mother's stomach.