Immune response in experimentally induced uremia. IV. Characterization of suppressor peritoneal macrophages in the uremic rat.

The effect of unstimulated uremia PM phi on the response of syngeneic control NA spleen cells to mitogens was examined. Nonstimulated PM phi purified from uremic rats were found to be significantly more suppressive than similar numbers of control PM phi. It was found that indomethacin treatment, as well as anti-la treatment, only partially reverses the suppressive activity of uremic PM phi as compared to control PM phi, thus indicating that uremic suppressor PM phi have different characteristics from control PM phi. In addition, uremic PM phi suppress via a suppressor factor released to the supernatant over 24 hr incubation. The enhanced suppressor activity of uremic PN phi as well as their different characteristics may have relevance to the severely suppressed cell-mediated immunity observed in uremia.