Ultracytochemistry of thymic epithelial cells in rats given organotin.
A combined light-and electron microscopic study of thymic changes in the adult rats after di-n-butyltin dichloride (DBTC) administration has been made. A rapid depletion of thymocytes in the cortex of thymus and subsequent rapid recovery of the number of thymocytes occurred. In this process, at 1-3 days after DBTC treatment the number of necrotic thymocytes was maximal. At 3-6 days, reticular epithelial cells were predominantly phagocytizing and acid phosphatase-positive in the cortex and cortico-medullary regions, where they appeared to develop from macrophage-like cells. During acute involution, it was likely that reticular epithelial cells were phagocytic and remove the necrotic thymocytes. The proportion of CD4+ CD8+ cells in the cortex of thymus was maximally reduced from day 3 onwards and reached the lowest level at 6 days after single oral dose of DBTC. On these days, the proportions of CD4- CD8- and single positive cell (CD4- CD8+ or CD4+ CD8-) subsets were relatively increased. These data suggest that DBTC preferentially causes an initial depletion of CD4+ CD8+ cells in thymus, and both macrophages and reticular epithelial cells of the cortex may be involved in the rapid removal of damaged thymocytes from thymus.
Mori
N
N
Department of Nutrition, School of Medicine, University of Tokushima, Japan.
Nakagawa
M
M
Kweon
M N
MN
Moriguchi
S
S
Kishino
Y
Y
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D004848:Epithelium / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009947:Organotin Compounds / Q000633:toxicity*; D051381:Rats; D011916:Rats, Inbred F344; D016176:T-Lymphocyte Subsets / Q000187:drug effects; D013950:Thymus Gland / Q000187:drug effects* / Q000201:enzymology / Q000648:ultrastructure
D009947:Organotin Compounds; C056189:di-n-butyltin; D000135:Acid Phosphatase; C020735:dibutyldichlorotin