The results showed that negative immunohistochemical stain occurred in brain tissue of rats afterbeing poisoned 7 dyas, but positive stain occured inthat of rats after 14 days.

• 结果表明染毒7d大鼠脑组织内未能检出吗啡，染毒14d大鼠脑组织内出现了强弱不一的免疫反应。