摘要Objective To investigate the effect of histamine type Ⅱ (H2) receptors of the CD+8 cells from aplastic anemia (AA) patients on the inhibition of hematopoiesis.Methods Employing the modification of the panning method with monoclonal antibody the CD+8 cells from peri-pheral blood mononulcear cells of 17 aplastic anemia patients were obtained. The ribs moved during thoracic operations from 17 patients with non-hematologic diseases were as normal bone marrow resource. According to different group 2×104/ml CD+8 cells from AA patients and/or 1.0×10-5 mol/L or 0.5×10-5 mol/L cimetidine alone or in combination were added in the normal CFU-GM cultures.Reusults The normal CFU-GM from the rib bone marrows was 147.69±24.75/105 cells (±s), if 2×104/ml CD+8 cells from AA patients were added in thecultures, the CFU-GM formation significantly decreased (89.49±20.49/105 cells, P<0.01). If CD+8 cells from AA patients and 1.0×10-5 mol/L or 0.5×10-5 mol/L cimetidine were in combination added in the cultures, the CFU-GM were 144.96±25.34/105 cells or 156.28±32.81/105 cells respectively, compared with normal group P>0.05. If 1.0×10-5 mol/L or 0.5×10-5 mol/L cimetidine was added alone in the cultures, the CFU-GM number were 110.47±27.46/105 cells (compared with control P<0.01) or 160.06±32.22/105 cells (compared with control P>0.05) respectively.Conclusion 1.0×10-5 mol/L and 0.5×10-5 mol/L H2 receptor antagonist cimetidine completely abolished the suppressive effect of CD+8 cells from AA patients on the growth of normal CFU-GM and lower concentration cimetidine (0.5×10-5 mol/L) didn't suppress the growth of normal CFU-GM.