AIM: To investigate effect of endotoxin on adrenomedulin(ADM) gene transcription in vascular endothelial cells. The role of p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway was also observed.METHODS: The effect of endotoxin in the presence or absence of p38 MAPK specific inhibitor SB203580 on the transcription of ADM in vascular endothelial cells ECV304 was evaluated by reverse transcription nest DNA polymerase chain reaction. RESULTS: Treatments of endotoxin (0.1, 1.0, 10, 50, 100 ?g/L) for 24 h increasea the ratios of ECV 304 ADM mRNA/? actin mRNA. The induction of ADM mRNA by endotoxin could be inhibited partially by 10 mmol/L SB203580.CONCLUSION: Endotoxin stimulated the transcription of ADM gene in vascular endothelial cells. The activation of p38 MAPK might be an important mechanism of ADM gene induced by endotoxin.