Effects of Diethylstilbestrol and Estramustine Phosphate (Estracyt) on Lymphoid Cell Populations and Mitogen Responsiveness in Male Mice

Abstract

Concentrations of diethylstilbestrol phosphate (DES-P) and estramustine phosphate (EMP) above 10-5 M in cultures of spleen lymphocytes from adult male mice resulted in a dose related inhibition of both Con A and LPS induced lymphocyte proliferation. Male mice injected with 5.6mg./kg. DES daily for 7 days had a significantly reduced responsiveness to both Con A and LPS compared to mice injected with olive oil only. Spleen lymphocytes from male mice treated with 100mg./kg. EMP showed a reduction of Con A induced mitogenesis whereas they exhibited a significantly enhanced response to LPS. The effects of DES and EMP on Con A and LPS induced blastogenesis were abolished within 2 weeks after cessation of treatment.DES treatment resulted in preferential depletion of splenic and lymph node T lymphocytes and a disproportionate T lymphocyte subpopulation with respect to Ly subclasses. Exposure to 30 or 100mg./kg. EMP resulted in a dose related loss of mononuclear cells both in spleen and lymph nodes.T lymphocytes predominantly of the Ly 1 phenotype were most sensitive to EMP. Co-cultures of spleen lymphocytes from normal mice and Mitomycin C blocked spleen cells from either normal or treated mice (DES or EMP) gave no convincing evidence of suppressor cell activity in the population of spleen mononuclear cells.