Altered TNF-{alpha}, glucose, insulin, and amino acids in islets of Langerhans cultured in a microgravity model system

1 Diabetes Research Laboratory, Program in Nutrition and Biochemistry and 2 Program in Physiology, Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, Georgia 31207; 3 National Space Biomedical Research Institute, Houston 77030; 4 Nutritional Biochemistry Laboratory and 5 Laboratory for Human Immune Function and Signal Transduction, Life Sciences Research Laboratories, National Aeronautics and Space Administration Lyndon B. Johnson Space Center, Houston, Texas 77058 The present studies were designed to determine effects of a microgravity model system upon lipopolysaccharide (LPS)-stimulated tumor necrosis factor- (TNF- ) activity and indexes of insulin and fuel homeostasis of pancreatic islets of Langerhans. Islets (1,726 ± 117, 150 islet equivalent units) from Wistar-Furth rats were treated as 1 ) high aspect ratio vessel (HARV) cell culture, 2 ) HARV plus LPS, 3 ) static culture, and 4 ) static culture plus LPS. TNF- (L929 cytotoxicity assay) was significantly increased in LPS-induced HARV and static cultures; yet the increase was more pronounced in the static culture group ( P