Correlation between the Fusion Dynamics of Cells Growing in vitro and Variations of Neutron Intensity Near the Earth’s Surface

Abstract

Kuzhevskii, Vashenyuk, Zhirov. † The experiments with cell cultures, which were carried out in the period of solar proton events accompanied by an increase in the rate of neutron counts near the earth's surface (the ground-level enhancements (GLEs)), have shown that, in the GLE period, cells of all cell lines began to fuse [1,2]. The time course of cell fusion in different cultures in the main peaks coincided with an increase in the rate of neutron count [3,4], which is determined by an increase in the intensity of secondary cosmic radiation near the earth's surface as a result of penetration into the atmosphere of high-energy particles of solar origin (solar cosmic rays) [3]. Neutrons could possibly underlie the phenomenon of cell fusion [3] because neutrons possess the highest biological efficiency among all other components of secondary cosmic radiation [5]. However, the effect of cell fusion during the GLE periods may be also affected by the neutrons that originate from the earth's crust [6][7][8][9][10]. It was shown in [11] that an exhalation of radioactive gases from the earth's crust may be increased in the periods of increased solar activity. In order to assess the biological efficiency of the neutron component near the earth's surface not only during the increase of its intensity (GLE period) but under the background variations of the neutron count rate as well, it is necessary to perform experiments during the period of quiet sun. The purpose of this study was to determine the nature of the relationship between the cell fusion in cell cultures and † Deceased. the background fluctuations in the rate of neutron counts near the earth's surface. Materials and methods.The experiments to assess the relationship between the cell fusion phenomena and the rate of neutron counts were performed August 19-23 and October 11-17, 1990. We performed four independent experiments at high latitudes ( 66.3° N, 33.7° E), which are characterized by a minimum threshold of the geomagnetic cut of cosmic rays (the hardness of the magnetic cut is 1 GV, which corresponds to the particles with energy >430 MeV [12]) and, hence, by both an intensity higher than at middle latitudes and possible biological efficiency of secondary cosmic rays near the earth's surface. The studies were performed with continuous cell lines growing in vitro : CHO, the Chinese hamster transformed-ovarycell line; FHM, the minnow ( Pimephales promelas ) tail-tissue-cell line; and RTG, the rainbow trout ( Salmo gairdneri ) gonad-cell line. A comparison of the state of cell cultures of different origin (fish and hamster), grown under similar conditions, and a comparison of identical cultures grown under different conditions (at 37°ë and at room temperature) allowed us to clarify the universal responses of cell cultures to the impact of the neutron component. Cell culturing and assessment of the cell-fusion index (the percentage of polynuclear cells in culture) were performed according to [1]. The data of uncorrected and corrected rates of neutron counts a...

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