Effect of short term benzene administration on circulating lymphocyte subpopulations in the rabbit: evidence of a selective B-lymphocyte sensitivity.

Repeated subcutaneous administration of benzene to rabbits (0.25 or 0.5 ml/kg/day) produced a progressive lymphocytopenia with a 80% reduction in total circulating lymphocytes after 10 days of treatment. This decrease in circulating lymphocytes was due primarily to a reduction in B- cells with 17-30% remaining after 10 days of treatment, depending on the dose. Immunoglobin surface receptor - negative cells, presumably T lymphocytes, were relatively unaffected until late in the experiment at the high dose. It is concluded that benzene has a relatively selective cytotoxic effect on circulating B-lymphocytes in the rabbit.