RESUMEN
<p><b>OBJECTIVE</b>To explore the action mechanism of the immune active components of sappon wood (SWE) for antagonizing reject reaction by observing the influence of its ethyl acetate extract on mRNA expression of myocardial GrB in rat model of allogenic ectopic cardiac transplantation.</p><p><b>METHODS</b>Animal model of abdominal cardiac ectopic transplantation was established taking Wistar rat as the donor and SD rat as the receptor. The successfully modeled rats were randomly divided into the model group, the SWE group and the CsA group. GrB mRNA expression was detected by RT-PCR method and myocardial pathomorphologic picture was observed in routine.</p><p><b>RESULTS</b>The pathologic changes in the SWE group (23 scores) and the CsA group (14 scores) were milder than in the model group (31 scores), the former two could markedly alleviate the myocardial pathologic injury (P<0.05, P<0.01). The GrB mRNA expression in the model group was 1.3000 +/- 0.1207, the SWE group 0. 7070 +/- 0.1215, and the CsA group 0.6700 +/- 0.0997, respectively; compared with the model group, the latter two could obviously down-regulate the expression of GrB mRNA (P<0.01) and no significant difference was found between the latter two groups (P>0.05).</p><p><b>CONCLUSION</b>SWE could alleviate the pathologic change, down-regulate the mRNA expression of myocardial GrB in allogenic ectopic transplanted myocardium of rats, it is possibly one of the factors for its antagonizing effect against reject reaction.</p>