RESUMO
To study the dynamics of venous plasma level of prostaglandin E_2 (PGE_2),and the relationship between PGE_2 level and immunity during and after CPB, 30 patients scheduled for open heart surgery served as the subjects. The peripheral venous blood samples were taken to measure plasma PGE_2 concentration,the expression of interleukin-2 receptor (IL-2R) on the lymphocyte membrane,and productive ability of interleukin-2 (IL-2),before and during CPB,on 1st ,7th and 14th day postoperatively,respectively. During CPB the PGE_2 level significantly ascended to the highest level,following cessation of CPB,went down but still remained higher level than baseline,even on 1st and 7th day postoperatively; Simultaneously, IL-2R expression and IL-2 generation were markedly suppressed, which were correlated negatively with the PGE_2 levels. It is suggested that cellular immunodepression induced by CPB,is partly related to the increase of plasma PGE_2, level.