Immunomodulation of cimetidine in mice

Cimetidine (Cim) 70 0r 10 mg/kg ip had immunopotentiation in normal mice and C57BL/6 mice-bearing Lewis lung carcinoma. Cim increased delayed type hypersensitivity (DTH) reaction and promoted the formation of plaque forming cells and specific rosette forming cells (SRFC). At 2.5 vg/ml Cim also promoted lymphocyte transformation of [3H] TdR ncorporation without concanavalin A. The suppressed hemolysin consentration fifty percent (HCs) and SRFC of tumor bearing mice were increased significantly by Cim. Ranitidine neither promoted DTH. HCso. SRFC and lymphocyte transformation in normal mice nor rose HC_o and SRFC in tumor bearing mice. The results suggested that histamine Hz receptors in T-suppressor cells are different from Hz receptors on stomach wall cells.