| pubmed-article:8574290 | pubmed:abstractText | We examined the effects of the long-term administration to mice of thyroid hormone or propylthiouracil (PTU) on lymphocyte subsets in spleens, and thymuses to clarify whether hyperthyroxinemia itself causes the changes in lymphocyte subsets, such as the marked increase in CD5+ B cells and decrease in natural killer (NK) cells, observed in hyperthyroid Graves' disease. Both the number and proportion of splenic NK (Thy-1+ asialo GM1+) cells were increased in hyperthyroxinemic mice treated with thyroxine (T4) for both short and long terms (8 and 32 weeks, respectively), those of splenic and thymic T (CD5+ sIgM-) cells and CD5-B cells were increased only in hypothyroxinemic mice treated with PTU for 32 weeks, compared with those in euthyroid mice. These data indicate that 1) long-term hyperthyroxinemia increases splenic and thymic T cells and splenic NK cells, but not CD5+ B cells, in mice, 2) long-term hypothyroxinemia induced by PTU treatment increases splenic B cells and CD5- B cells, and 3) hyperthyroxinemia itself does not cause the changes in CD5+ B cells and NK cells, which are observed in hyperthyroid Graves' disease, in mice. | lld:pubmed |
