Abstract: | The ability of spleen, thymus, and bone-marrow cells of intact (control) and hydrocortisone-treated (experiment) CBA mice to induce a lymph node graft versus host reaction (GVHR) in (CBA×C57BL)F1 hybrids was compared. After injection of hydrocortisone into the donors in a dose of 2.5 mg per mouse their spleen cells induced a more active GVHR, as shown by an increase in the lymph node indices and in the percentage of immunoblasts in the regional (popliteal) lymh node compared with the control. After transfer of thymus cells of hydrocortisone-treated donors the number of immunoblasts was higher than, but the weight of the lymph node was almost the same as in the control. Conversely, after injection of bone marrow cells from hydrocortisone-treated donors, the lymph node enlarged whereas the percentage of immunoblasts did not increase above the control. Consequently, when the increase in the hydrocortisone level is exogenous in nature, the cell populations of the spleen and thymus contain a higher proportion of T lymphocytes, which respond by proliferation to contact with H alloantigens.Institute of Clinical and Experimental Medicine, Academy of Medical Sciences of the USSR, Siberian Branch, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 458–459, October, 1977. |