Objective: To investigate the effect of histamine type II (H2) receptors on the inhibition of hematopoiesis by CD8+ cells from aplastic anemia (AA) patients.
Methods: The effects of CD8+ cells and/or cimetidine, alone or in combination, on normal human CFU-GM growth were studied by using CFU-GM assay.
Results: The CD8+ cells from the peripheral blood of AA patients significantly suppressed the growth of normal allogeneic CFU-GM. This inhibitory effect could be blocked by 0.5 x 10(-5) mol/L or 1.0 x 10(-5) mol/L cimetidine. 1.0 x 10(-5) mol/L cimetidine alone slightly inhibited the growth of normal CFU-GM, but 0.5 x 10(-5) mol/L cimetidine did not.
Conclusion: H2 receptor antagonist cimetidine abolished the suppressive effect of AA patients CDB+ cells on the growth of normal CFU-GM.