ABSTRACT
Objective: To investigate the role and mechanism of histamine in regulation of C57BL/6 mice spleen derived LAK activity in vivo. Methods: The C57BL/6 mice carrying B16 pulmonary metastatic melanoma were treated with LAK/IL 2/histamine therapy or LAK/IL 2 therapy with the aim of evaluating both anti tumor responses in vivo. Results: It was found that the addition of histamine effectively potentiated the anti metastatic effect produced by LAK/IL 2 therapy and induced regression of NK resistant B16 pulmonary metastatic melanoma. Survival period was significantly prolonged in mice receiving LAK/IL 2/histamine as compared with LAK/IL 2 therapy alone. The effect of histamine was completely blocked by H 2 R antagonist ranitidine, and mimicked by dimaprit, a H 2 R agonist. Conclusion:Histamine, via specific activation of H 2 R, may be an important regulator of LAK cells activity; histamine and LAK/IL 2 synergistically induce more potent antitumor efficacy in vivo .