Organism in conditions of altered gravity
Experimental material accumulated in gravitational biology suggests that the basis of the regulatory processes aimed at preservation and maintenance of physiological homeostasis in altered gravity, are the molecular and cellular mechanisms of adaptation. Obtained in gravitational biology results allowed to formulate a hypothesis about the mechanism of gravity sensitivity of single-celled organisms. The essence of this hypothesis is that gravitational sensitivity (tolerance) of single-celled organism as an individual independent and self-sufficient biological system is a function of its metabolic and physical activity. This means that the main condition for determining the gravitational sensitivity of single-celled organisms are not their form and dimensions, but their functional activity.
There is also reason to believe that the effects of altered gravity on living systems are implemented through regulatory mechanisms. It relates to regulation, especially of processes such as proliferation, differentiation and specialization of cells and tissues, recovery reaction and regeneration. The main connecting link between the cell and higher levels of organization in the chain of functional rearrangements occurring in living systems in the process of adaptation to new conditions of existence is the regulation of metabolism. Determination of the ways and valuation of the mobilization of energy resources necessary to maintain and preserve the homeostasis of the cell and restore the constancy of the internal environment of the organism as a whole, as well as the control mechanisms of homeostasis, apparently, is done by constant and reliable interaction between the molecular, neuron/moral and endocrine systems, respectively, at the cellular, tissue, organ and organismal and population levels.
The range of gravitational biology tasks is broad and is not limited only to the above tasks. To create a comprehensive picture it is very important constantly receive the information about the behavior of the organism, developing in the conditions of altered gravity.
Gravity-dependent processes in biological systems of various organization levels (2001-2005) / Гравитационно-зависимые процессы в биологических системах различных уровней организации (2001-2005 гг.) (312.0 KiB)
Research in the field of gravitational biology (2001-2005) / Исследования в области гравитационной биологии (2001-2005 гг.) (358.4 KiB)
Russian-Ukrainian joint research program in the field of space biology / Программа совместных российско-украинских исследований в области космической биологии (238.2 KiB)
Cellular mechanisms of adaptation
Adaptation (adaptation) of organisms to environmental conditions, being one of the main criteria of natural selection, acts as the driving force of biological evolution. Speed, efficiency and the energy “cost” of adaptation determines the degree of sustainability of each individual species to adverse environmental conditions in the course of its individual development.
In the process of “vertical” evolution, leading to higher levels of biological organization, with the extension of the range of compensatory-adaptive reactions that provide for an organism environmental resistance, as a rule, a decrease of the overall resistance of the living system takes place. It follows that the sustainability of free-living unicellular organism or single cells operating in the composition of organs and tissues is always higher than the sustainability of a multicellular organism. This sustainability is achieved, primarily, due to the non-specificity of cell responses to the actions of environmental factors (physical, chemical or biological).
Studies on cell cultures occupy a significant place in space biology and medicine. The use of cells and tissues isolated from the organism of animals and plants, and populations of single-celled organisms, is extremely useful for studying effects of altered gravity to register the initial stages of the development of the living systems response at the cellular level. However, the observed changes in the structural and functional status of cell is often a result (echo) of the shift of the physiological characteristics of a multicellular organism, occurring at the system level under the effect of the environmental factors, including change of the gravity vector magnitude and direction. The study of the characteristics and depth of transformation processes occurring in the structural organization and functional activity of cell, gives the opportunity to evaluate the physiological significance and the energy “cost” of adaptation of the whole organism to new conditions of existence, for example, to the conditions of microgravity.
The studies clearly revealed opposite effects of altered gravity depending on cell type and their ecological and physiological characteristics (metabolic rate, physical activity and environment). It was shown that, by varying the force of gravity as a variable, the growth rate and the rate of cell division, and, consequently, the biomass growth can be regulated. This gives the possibility to optimize the biotechnological processes in the cultivation of populations of cells and single-celled organisms in the context of the gravity vector magnitude and direction change.
Comparative analysis of results of biological research carried out to date on board of SC (manned and unmanned) identified during this period a complex of inherent abnormalities in the physiological status of the body of the astronaut, and clearly points to the fact that the basis of these deviations are violations of regulatory processes at the cellular level.
Moreover, the system of preventive measures aimed at normalization of physiological functions of the human body during space flight and post-flight period, is developed taking into account the peculiarities of changes in the structural organization and metabolic activity of the cells. Currently, the extensive empirical experience of medicine allows to some extent to correct these deviations, but completely eradicate the consequences of long influence of space flight factors on the organism, apparently, will be possible only after the solution of fundamental problems associated with the study of cellular mechanisms of adaptation. In our opinion, the most promising strategic line of research in space biology is the study of causal relationships between changes at the level of the whole organism and cellular mechanisms underlying them. A prerequisites for the solution of this problem, from our point of view are first – the identification and classification of gravity sensors (non-specialized intracellular gravireceptors) and secondly, deciphering of the molecular mechanisms of their functioning. The main solution to this problem should be to study molecular mechanisms of perception and realization of the gravity stimulus in the cell, i.e. the functioning of gravireceptors.
Justification of the non-specificity principle of molecular and cellular mechanisms of biological systems adaptation / Обоснование принципа неспецифичности молекулярных и клеточных механизмов адаптации биологических систем (215.7 KiB)
The use of cell cultures for solving fundamental and practical problems of space biology and biotechnology / Использование культур клеток для решения фундаментальных и практических задач космической биологии и биотехнологии (292.6 KiB)
Research in the field of cell biology / Исследования в области биологии клетки (276.2 KiB)
Cell culture studies (proposals to the MIR-NASA program) / Исследования клеточных культур (предложение к программе МИР-NASA) (219.6 KiB)
Molecular and cellular mechanisms of gravitational sensitivity of biological systems / Молекулярные и клеточные механизмы гравитационной чувствительности биологических систем (196.1 KiB)
Provision of long-term space flights
Risks that a man faces when going to space flight increase in proportion to its duration. In the conditions of flights to Mars or to the Moon with a prolonged stay on their surface, the crews will have to work actively on these celestial bodies after a long stay outside the protective shell of the Earth. There is therefore an urgent need to understand the huge number of interacting factors that influence the condition of skeletal-muscular apparatus and sensory systems, immune system, sensitivity to radiation, carcinogenesis, i.e. to understand the complex psychological and physiological changes that occur under the combined action of microgravity and increased levels of ionizing radiation.
The main difficulty is to be able to diagnose the nature and extent of the changes developing in the body as a whole and on individual systems and organs of it, and carry out preventive measures aimed at maintaining an optimum level of health and performance of crews. The most reliable from the point of view of time-consuming and ethical standards way to decode the physiological effects of space flight factors is the development of integrated programs of studies on animals, cell cultures and human beings. The main goal of such programs is to obtain timely information necessary for the development of therapeutic interventions that will allow people to go further beyond the protecting earth’s biosphere, ensuring their safety and productivity.
Long-term forecast of the state of human health during prolonged space flight and maintaining the physiological status of the organism in the conditions of the main space factors (microgravity, radiation of various intensities, hypo – and a-magnetic field) require more in-depth study of the foundations of the influence of these factors on the living systems of the organism. With this purpose, the creation of new concept is necessary, based on critical analysis of data on the physico-chemical basis of the cell regulatory systems and morphogenesis processes in conditions of the environmental factors of space flight, including gravitational forces, radiation and magnetic fields.
Research program in the framework of this concept involves on the first stage the organization of scientific cooperation, temporary functional research teams, search, experimental evaluation and analysis of scientific information, creation of data bank and knowledge bank on the problem, evaluation and choice of research strategy (theoretical and experimental) and the development of the concept of positional homeostasis of biological systems (cellular model) in a gravitational field.
The concept studies of the mechanisms of adaptation of living systems to the conditions of long-duration space flight / Концепция исследований механизмов адаптации живых систем к условиям длительного космического полета (111.8 KiB)
Project "MARS". The program of biomedical support of space flight with the 2.5 year duration / Проект "МАРС". Программа медико-биологического обеспечения космического полета длительностью 2,5 года (216.0 KiB)
Fundamental research in space biology (NASA, 2001-2012) / Фундаментальные исследования по космической биологии (NASA, 2001-2012) (280.3 KiB)