Residual radiation effect in the murine spleen. In situ measurement by 125-iodo-deoxyuridine retention.
To investigate whether residual radiation damage in hematopoietic tissue is measurable in situ by a change in cell turnover, the retention of the thymidine analogue 5-(125-I)iodo-2'-deoxyuridine (125-IUdR) following incorporation into DNA of cells in bone marrow and spleen of mice was measured 35 days after 0-500 rad whole body gamma irradiation. In the bone marrow a rapid and a slow turnover component of 125-IUdR retention were found. Both components were almost identical for unirradiated and irradiated mice. In the spleen the 125-IUdR retention curves exhibited three components with increasingly prolonged half-times. In the second component the half-time was longer in irradiated than in unirradiated mice. This was dose-dependent. The increased half-time of 125-IUdR retention in irradiated spleens may be caused by direct cellular damage of long-lived cells (lymphocytes, early hematopoietic progenitor cells) or/and by diminished stimulation of proliferation by microenvironmental or long-range factors.
D000818:Animals; D001853:Bone Marrow / Q000378:metabolism / Q000528:radiation effects; D002455:Cell Division / Q000528:radiation effects; D005260:Female; D007065:Idoxuridine / Q000378:metabolism*; D007457:Iodine Radioisotopes; D051379:Mice; D013154:Spleen / Q000378:metabolism / Q000528:radiation effects*; D013997:Time Factors; D014916:Whole-Body Irradiation
D007457:Iodine Radioisotopes; D007065:Idoxuridine