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Biomedical subjects

L V Serova

Publications and source records attributed to L V Serova.

At least 19 recordsLinked to original sources
PubMed2005

[Reproductive function and viability of progeny in female rats under unfavourable influences in run up to puberty].

Wistar female rats were subjected to a 3.5-day water deprivation once a week in the period of 1.5 to 3 months of age. Their progeny was subjected to the same influences during the same period of life. A week later, reproductive function of female rats was evaluated by mating them with normal males. In the experimental groups of both generations, no significant changes were found in number of neonates and their body mass, in maternal behaviour during the lactation period, in postnatal mortality of pups, in their growth and development, in motor activity, physical endurance and behaviour.

Animals↗
PubMed2004

Ontogenesis of mammals and gravity.

The results of the experiments with Wistar rats in microgravity and 2G hypergravity are summarized. Their analysis allows to conclude that adaptive potentials of adult animals in space flights lasting up to 1/50 of their life span are enough for maintenance of adequate reactions to acute and chronic stressors in the postflight period, rapid elimination of space-induced metabolic and structural alterations on return to Earth, maintenance of normal reproductive function after space flight. In embryological experiments it was demonstrated that during space flight it is possible not only to maintain physiological functions of an adult organism, but to form functions of a developing fetus. The animals that spent the portion of their prenatal development in space flight were capable to go through the entire cycle of postnatal development, up to sexual maturity and reproduction. In ground based centrifuge experiments with 2G it was demonstrated the possibility of realizing, under hypergravity, of all the main stages of prenatal and early postnatal development of rats: fertilization, embryon implantation, fetal development, birth and lactation of progeny. Exposure of rats to microgravity did not reduce their life span post flight. Alterations in biological age of animals were small.

Adaptation, Physiological↗
PubMed2003

[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.

Adaptation, Physiological↗
PubMed2002

[Microgravity, life span and biological age of animals].

Summarized are author's and literary data about the microgravity effects on life span and biological age of animals obtained in experiments with laboratory rats flown in biosatellites Kosmos. Exposure of rats in the spaceflight microgravity as long as 3 wk. (up to 1/50th of the life period of this species) did not reduce the life span post flight. Alterations in biological age as judged by the reproductive function, general resistance and tissue regeneration rate were minor and in a number of parameters were significantly less as compared with the shifts resulting from simulation of the physiological effects of microgravity in laboratory (for a similar period). Prospects of investigations into this problem are considered.

Animals↗
PubMed2001

[Microgravity and development of the mammals: problems results prospects].

The author reviews results of 20-yr in-space and laboratory investigations into the effects of hypergravity (2 g) and hypokinesia (immobilization, suspension, water deprivation). It was found out that the compensatory and adaptive potentials of mammalians (Wistar rats) in microgravity are sufficient to let proceed pregnancy, and activate anabolic processes associated with fetus growth and water-salt homeostasis maintenance. In a number of aspects effects of microgravity on the mother-fetus systems appear to be less significant than of various factors on Earth including the conventional models of microgravity. In all types of experiments, fetus state was determined by mother's well-being, compensatory and adaptive potentials. Under the disadvantageous conditions, survival of fetus cost dramatic shifts in mother's organism. Outlined is a long-range program of research on the problem and feasibility of an experiment in which mammalians will pass the overall life cycle in space flight.

Animals↗
PubMed2001

Microgravity and aging of animals.

A study of changed gravity effects upon viability, life span and aging is of interest, on one hand, from a practical viewpoint in relation to the growing duration of space missions and on other hand, from a theoretical viewpoint, because gravity is one of the key factors in the evolutionary process on the Earth. In 1978 special conference titled "Space Gerontology" was held. Well known experts in space biology and physiology of aging participated in it. However, all the materiales presented at the conference were based on analogies and on what could be during exposure to microgravity rather than on real data. I shall try to discuss this problem, basing on the results of rats experiments on board "Cosmos" biosatellites and ground based model experiments. Male wistar rats examined after 1-3 weeks exposure to microgravity on board biosatellites demonstrated some changes similar to the signs [correction of sings] of aging, such as decreased motor activity, thymus involution, muscle atrophy, osteoporosis etc. But all these changes were reversible and in rats examined 3 weeks after return to the Earth we did not find any deviations from the controls.

Aging↗
PubMed1999

[The influence of hypokinesia on the mother-fetus system].

In experiments with rats effects of hypokinesia on the course of pregnancy and the mother-fetus system were investigated. Immobilization in penal-type cages of female rats on days 8 through to 19 of pregnancy gave rise to significant shifts in mother's organism, i.e. retarded body mass gain, mass reductions in thymus, spleen, liver, some other organs, and adipose tissue. Rates of prenatal fatality in the experimental group were not changed; yet, fetuses were behind the control by the values of body mass, ossification ranges, development of analyzers and other parameters. Quantities of liquid, sodium, magnesium and calcium per one gram of dry tissue were equal in the experimental and control fetuses. Comparison of the data with results of the embryological experiment with rats aboard the space "shuttle" suggests that immobilization is more baneful for the mother-fetus system than microgravity of the same length.

Animals↗
PubMed1998

[Effect of weightlessness on rats endocrine system development].

The histological structure of the brain and spinal cord, visual, olfactory, auditory and vestibular analysers, and endocrine organs (epiphysis, hypophysis, thyroid and parathyroid glands) were investigated in newborn rats delivered by females who had been exposed to weightlessness a half of the pregnancy period. Analysers of the flight animals did not have any marked deviations from the norm. Loci of neurone degeneration resembling porencephaly but less massive were revealed in various brain portions (cortex, hypocampus, metencephalon, spinal cord) of the infant rats developed in space flight. Endocrine studies showed accelerated differentiation of the thyroid cells secreting thyroid hormones, C-cells, and parathyroid cells in most of the infant rats of the flight group. The test animals reduced the size of epiphysis and the number of pinealocytes. Adenohypophysis was found to be smaller with altered spatial distribution of the trabecular system. The changes look quite impressive but do not threaten viability of the animals.

Animals↗
PubMed1996

[Adaptive potentials of mammals under conditions of weightlessness].

Review and analysis of experiments with Wistar rats in microgravity allows to deduce that compensatory-adaptive potentials of mammals in space flight lasting up to 1/50th of their life span suffice for rapid elimination of space-induced metabolic and structural alterations on return to Earth, maintenance of adequate reactions to acute and chronic stresses in the post-flight period, demonstration of a stereotype of pre-flight elaborated conditional reflexes and pregnancy dominant, normal reproductive function and life span. Consideration is given to individual differences in body responses to the micro-g environment. A conclusion is made to the effect that the role of individual stamina and reactivity will be gaining in importance with increasing duration of space flights.

Adaptation, Physiological↗
PubMed1996

[Effect of weightlessness on the mother-fetus system (results of embryological experiment NIH-R1 abroad the "Space Shuttle"].

Female rats were exposed to weightlessness in the mid-deck of US "Space Shuttle" in the period between days 9 to 20 of pregnancy and examined on Earth post flight. No significant structural anomalies threatening the life and normal development were found in newborn rats carried by mothers under the conditions of weightless exposures. Water, Na, K, Ca, Fe and Cu contents in fetal and placental tissues of the flight animals were not changed. Differences between the flight and ground-based synchronous controls, or the rates of formation of the fetal skeleton were not revealed. Comparison of these data with results of the experiment aboard biosatellite "Cosmos 1514" in which female rats stayed in weightlessness from day 13 to 18 of pregnancy indicates that the two-fold increase of space flight duration did not add changes in the state of fetuses.

Animals↗
PubMed1995

[The redistribution of calcium ions and organic substances in pregnant rats under extreme conditions].

It was found that under water deprivation the liver, spleen, white and brown fat decreased in weight in rats whereas the weight of the heart, kidneys and uterus with fetuses did not differ from the control. In pregnant rats, water deprivation led to involution of thymus and hypertrophy of adrenals, decrease in the calcium ions content in the liver and kidney and reducing of the liver and some other organs weight. A similar picture was observed during space flight in pregnant rats. The data obtained suggest a redistribution of organic and inorganic substances under water deprivation.

Animals↗
PubMed1995

[Water-salt homeostasis in rats during space flight].

The paper generalized the results of s series of experiments aimed at studying liquid and electrolytes contents in various organs and tissues of rats following 3-week space flights (SF). The results ascertain high reliability of the water-salt homeostasis maintaining system which ensures stable water and electrolytes amounts in the majority of animal tissues in SF. The following alterations appear to be of greatest significance: deduced potassium levels in the heart ventricle tissues in male rats after short-duration (7-9 d) exposure in SF, zero-g-induced degradation of the body ability to bind potassium at injection of isotonic solution KCl into the stomach; redistribution of potassium ions between mother and developing fetuses in space experiments with pregnant animals. Simulated experiments showed that similar shifting of potassium ions in the mother-fetus system may be due not to weightlessness exclusively but other impacts, i.e. they are not specific.

Animals↗
PubMed1993

Changing gravity level and the development of animals.

Space biology has accumulated a great body of information concerning the influence of microgravity upon objects of varying levels of biological organization: from microorganisms to higher animals and humans. However, the choice of biological objects was in most cases random, and there has been no attempt at a comparative biological analysis of the results obtained. A similar situation is noted in hypergravity research, where responses in various animal classes are compared mainly with respect to differences in body masses rather than in the level of biological organization. Without any claims to solve this serious problem in this presentation, I'll try to at least raise it, using as a starting point the conception about evolution of resistance and reactivity, created by my teacher N.N. Sirotinin (1981).

Acceleration↗