Fate of thymocytes: studies with 125I-iododeoxyuridine and 3H-thymidine in mice.
Cortical thymocytes of young adult mice were labeled in situ with radioactive DNA precursors. As a result of cell emigration and cell death, total thymic radioactivity decreased within 8 days to 10% or less of that present on day 1. Accumulation of thymic migrants in peripheral lymphoid organs was estimated by computing the net thymus-derived radioactivity in these tissues. Thymic cell death was assessed by comparing values obtained with 125I-UdR to those acquired with 3H-TdR; The results indicate that cortical thymocytes migrate to the spleen, mesenteric lymph node, femurs and intestine; nevertheless, only a small fraction of the activity originally present in the thymus was recovered in these organs; the vast majority of newly formed cortical thymocytes apparently die after a relatively short life span. Exclusive of the fraction which dies in situ, evidence for thymocyte death is seen in bone marrow; however, most migrants appear to terminate in the intestine.
D000818:Animals; D002465:Cell Movement; D002470:Cell Survival; D005260:Female; D005269:Femur / Q000166:cytology; D007065:Idoxuridine; D007422:Intestines / Q000166:cytology; D007457:Iodine Radioisotopes; D008198:Lymph Nodes / Q000166:cytology; D008643:Mesentery; D051379:Mice; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000166:cytology*; D013936:Thymidine; D013950:Thymus Gland / Q000166:cytology*; D014316:Tritium
D007457:Iodine Radioisotopes; D014316:Tritium; D007065:Idoxuridine; D013936:Thymidine