title: Lymphatic tissue changes in rats flown on Spacelab Life Sciences-2.
abstract: Thymus, spleen, inguinal lymph node, and bone marrow specimens from rats flown on the 14-day Spacelab Life Sciences-2 mission were examined after staining of tissue sections. The primary observation was a transient retrogressive change in lymphatic tissues in the rats within a few hours after landing. There was a diffuse increase in tingible body-containing macrophages in the cortex of the thymus, thymus-dependent areas of the splenic white pulp, and inguinal lymph node. This was not observed 9 days after recovery. The in situ labeling of fragmented DNA strands catalyzed by exogenous terminal deoxynucleotidyltransferase (TdT) with ApopTag reagents (Oncor, Gaithersburg, MD) inside the tingible body-containing macrophages indicated that the process was one of apoptosis. No increase in tingible body macrophage activity was noted in thymus and spleen tissue obtained from rats in flight on flight day 13. The reaction to gravitational stress from readaptation to 1 G is the most likely explanation of the transient retrogressive change in lymphatic tissues.
authors.affiliation: Department of Medical Biology, University of Tennessee Medical Center at Knoxville 37920, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Congdon
authors.forename: Z
authors.initials: Z
authors.lastname: Allebban
authors.forename: L A
authors.initials: LA
authors.lastname: Gibson
authors.forename: A
authors.initials: A
authors.lastname: Kaplansky
authors.forename: K M
authors.initials: KM
authors.lastname: Strickland
authors.forename: T L
authors.initials: TL
authors.lastname: Jago
authors.forename: D L
authors.initials: DL
authors.lastname: Johnson
authors.forename: R D
authors.initials: RD
authors.lastname: Lange
authors.forename: A T
authors.initials: AT
authors.lastname: Ichiki
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015415:Biomarkers; D001835:Body Weight / Q000502:physiology; D001853:Bone Marrow / Q000502:physiology; D001854:Bone Marrow Cells; D053938:DNA Fragmentation / Q000502:physiology; D004253:DNA Nucleotidylexotransferase / Q000378:metabolism; D006112:Gravitation; D006651:Histocytochemistry; D008208:Lymphatic System / Q000166:cytology / Q000502:physiology*; D008214:Lymphocytes / Q000502:physiology; D008297:Male; D009929:Organ Size / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013026:Space Flight; D013154:Spleen / Q000166:cytology / Q000502:physiology; D013950:Thymus Gland / Q000166:cytology / Q000502:physiology
chemical_list: D015415:Biomarkers; D004253:DNA Nucleotidylexotransferase