Alteration of lipid composition of rat thymus during thymic atrophy by whole-body X-irradiation.
OBJECTIVE
Thymic atrophy induced by irradiation is well known, but in vivo lipid metabolism during the atrophy has not been studied in detail. We determined the lipid composition of rat thymus during the progress of thymic atrophy induced by whole-body X-irradiation.


METHODS
The lipid analysis of total lipid of rat thymus after 5 Gy whole-body X-irradiation was performed by high performance liquid chromatography and gas chromatography equipped with mass spectrometry.


RESULTS
Major changes observed were a 16.2-fold elevation of cholesterol ester (CE) during a 48-h post-irradiation period and a 6.1-fold increase of alkyldiacylglycerol (ADG) at 24 h. Other significant changes detected were an increase in lysophosphatidylcholine and a transient increase in ceramide and phosphatidic acid. Acyl chain analysis revealed a substantial elevation of arachidonate composition of CE and an unusually high content of polyunsaturated fatty acids (71.5%, mol/mol) in ADG.


CONCLUSIONS
Lipid analysis shows that the thymic atrophy by X-irradiation was accompanied by a significant change in thymic lipids. This in vivo result opens up new vistas of the role of lipids in apoptosis and phagocytosis during thymic atrophy.
Department of Chemistry, Seoul National University, Seoul, South Korea.
Heung Soon
HS
Park
Sungyeul
S
Kim
Youngkyun
Y
Lee
Myung Sun
MS
Choi
Myung-Un
MU
Choi
D000818:Animals; D001284:Atrophy / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D005260:Female; D050356:Lipid Metabolism / Q000528:radiation effects*; D008206:Lymphatic Diseases / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D011832:Radiation Injuries / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013950:Thymus Gland / Q000378:metabolism* / Q000473:pathology* / Q000528:radiation effects; D014916:Whole-Body Irradiation / Q000009:adverse effects*