SUPPRESSION OF SPLENIC T-LYMPHOCYTE PROLIFERATION BY ACUTE COCAINE ADMINISTRATION

We have recently demonstrated that cocaine administration has a limite d effect on mitogen-stimulated T lymphocyte proliferation. The present study investigated the effect of cocaine on splenic T cell response t o alloantigens. Rats received intraperitoneal injections of cocaine HC l, and splenocytes were isolated either thirty minutes or three hours post-adm in ist ration. In the thirty minute exposure group, cocaine a t 10.0 and 25.0 mg/Kg/B.Wt. suppressed (p<0.05) T cell proliferation i n mixed lymphocyte cultures. Compared to control data, proliferation w as decreased by 46.6% and 56.4%, respectively. However, this effect wa s not as pronounced in cells isolated three hours post-administration, indicating a transient inhibition of T cell function by cocaine. The decrease in splenic T cell proliferation in response to alloantigens i n the thirty minute exposure group did not reflect alterations in calc ium influx or IL-2 production. Although this study did not ascertain t he exact mechanism of inhibition, these results demonstrate that short -term cocaine exposure can alter T cell reactivity to alloantigens, su ggesting a reduction in the functional status of these cells.