Fischer Rat Thyroid Low Serum 5% (Fischer Rat Thyroid Low Serum 5) - 07.15.14
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Science Objectives for Everyone Fischer Rat Thyroid Low Serum 5% (FRTL5) is aimed at assessing the effects of microgravity and radiation on rat thyroid cells. This experiment should provide further indications that may help in understanding why the sensitivity of the cells to radiation damage is related to their cell cycle and to the kinetics of the radiation. Furthermore it will help improve our knowledge of the effect of the space environment on the human body, especially on long-duration missions.
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The thyroid produces hormones that affect heart rate, blood pressure, body temperature, weight, and calcium balance in the body. This study assessed space effects on rat thyroid cells to improve our overall knowledge of how space affects human hormones. Data also help scientists to understand how cell sensitivity to radiation damage is related to the cell cycle and the kinetics of the radiation. Results indicate that overall cell number is lower in cultures exposed to microgravity, most likely due to a slower growth rate, which is reversible. Further research is needed to verify and validate the data and investigate the molecular mechanisms at work.
Udine University, Udine, , Italy
Sponsoring Space Agency
European Space Agency (ESA)
ISS Expedition Duration
October 2004 - October 2005
Previous ISS Missions
- Fischer Rat Thyroid Low Serum 5% (FRTL5) will validate finding about the sensitivity of cells in proliferative state to the space environment compared to those in physiological stand-by. This finding could have a major impact on space biology and physiology studies.
This experiment is aimed at assessing the effects of the Space environment (microgravity and radiation) on normal in vitro cultures of rat thyroid cells. This unique in vitro test system allows for the use of cells in a quiescent state (non proliferating), which can be kept almost indefinitely without culture medium exchanges or any manipulation.
The cell type chosen are the Fischer Rat Thyroid Low Serum 5% (FRTL5) rat thyroid cell strain, hence the name of the experiment. One of the reasons for choosing these specific thyroid cells is the relevance they have to human physiology and medicine. Thyroid tissue is an ideal target for Space radiation research. The thyroid is a major endocrine gland, central in hormonal regulation in man.
Thyroid tissue has been reported to be strongly resistant to the acute effects of radiation. On the other hand, follow-up studies on human subjects which had been variably but heavily irradiated in Hiroshima, Nagasaki, the Marshall Islands and more recently in Chernobyl, clearly demonstrated a significant long-term sensitivity of thyroid tissue to radiation in terms of development of tumors.
The FRTL5 cells will be used as a biological system to measure radiation and microgravity effects. This experiment should provide further indications that may help in understanding why the sensitivity of the cells to radiation damage is related to their cell cycle and to the kinetics of the radiation. Furthermore it will help to improve our knowledge of the effect of the space environment on the human body, especially with longer-term missions planned in the future (e.g. Mars).
The FRTL5 cells will be placed in culture flasks. Each one is made of optically clear polystyrene with a 75 cm2 available growth area, which has the right surface structure that is specially treated for optimal attachment and growth of cells. The flasks will contain FRTL5 cells within a culture that contains a thyroid stimulating hormone. This is a hormone normally secreted by the pituitary gland, which stimulates the thyroid cells to produce thyroxine. The sealed flasks will be accommodated in a plastic bag and all the flasks will be placed in a closed plastic container. The experiment set up makes it possible to preserve the cells for a long time being stimulated by thyroid stimulating hormone. This can be done without any exchange of the culture medium in which the cells are placed and without any manipulation. The cells will be tested on return to Earth for DNA modifications due to radiation and magnetic fields, and the effect of weightlessness on cell behavior. In evaluating the response of cells to the thyroid-stimulating hormone, cells will be analyzed for indications of mutation and changes in complex cell behavior such as programmed cell death, and duplication efficiency. For comparative purposes, these samples will be analyzed against samples from a duplicate experiment, which takes place at the same time with the same procedures on Earth.
Overall cell number is lower in the cultures exposed to space environment as compared to the ground controls reproducing the temperature conditions during the ENEIDE mission. This phenomenon is most likely related to a slower growth rate in proliferative state. This slow growth rate is: reversible, as demonstrated by the results of the growth curves, the plating and cloning efficiencies measured on the samples once they have been returned to our laboratory in Udine; and mostly related to space effects as indicated by additional control in a clinostat. More experiments of this kind are needed to verify and validate these data and to investigate the molecular mechanisms underlying the phenomenon.
Albi E, Albi E, Ambesi-Impiombato FS, Villani M, De Pol I, Spelat R, Lazzarini R, Lazzarini R, Perrella G. Thyroid Cell Growth: Sphingomyelin Metabolism as Non-Invasive Marker for Cell Damage Acquired during Spaceflight. Astrobiology. 2010; 10(8): 811-820.
Meli A, Perrella G, Toller M, Zambito AM, Spelat R, Moretti M, Ferro F, Curcio F, Ambesi-Impiombato FS. FRTL-5 experiment during ENEIDE mission. Microgravity Science and Technology. 2007 September; 19(5-6): 175-179. DOI: 10.1007/BF02919476.
Ground Based Results Publications
The information on this page is provided courtesy of the ESA Erasmus Experiment Archive.