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Journal of Biomedicine and Biotechnology
Volume 2009, Article ID 125412, 5 pages
http://dx.doi.org/10.1155/2009/125412
Research Article

Nuclear Phosphatidylcholine and Sphingomyelin Metabolism of Thyroid Cells Changes during Stratospheric Balloon Flight

1Department of Clinical and Experimental Medicine, Physiopathology Section, School of Medicine University of Perugia, 06100 Perugia, Italy
2Polispecialistica Bios, 88900 Crotone, Italy
3Department of Experimental and Clinical Pathology and Medicine, University of Udine, 33100 Udine, Italy

Received 2 July 2009; Accepted 16 September 2009

Academic Editor: Yusuf Hannun

Copyright © 2009 Elisabetta Albi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Nuclear sphingomyelin and phosphatidylcholine metabolism is involved in the response to ultraviolet radiation treatment in different ways related to the physiological state of cells. To evaluate the effects of low levels of radiation from the stratosphere on thyroid cells, proliferating and quiescent FRTL-5 cells were flown in a stratospheric balloon (BIRBA mission). After recovery, the activity of neutral sphingomyelinase, phosphatidylcholine-specific phospholipase C, sphingomyelin synthase, and reverse sphingomyelin synthase was assayed in purified nuclei and the nuclei-free fraction. In proliferating FRTL-5, space radiation stimulate nuclear neutral sphingomyelinase and reverse sphingomyelin synthase activity, whereas phosphatidylcholine-specific phospholipase C and sphingomyelin synthase were inhibited, thus inducing sphingomyelin degradation and phosphatidylcholine synthesis. This effect was lower in quiescent cells. The possible role of nuclear lipid metabolism in the thyroid damage induced by space radiations is discussed.