探讨了褪黑素（ｍ ｅｌａｔｏｎｉｎ，ＭＴ）三个剂量［２５、７５、１２５ ｍ ｇ／（ｋｇ·ｄ）］、美沙酮两个剂量［２、４ｍ ｇ／（ｋｇ·ｄ）］及ＭＴ 长期保护用药等方法，对按剂量递增法形成的海洛因依赖性大鼠血液中的ＳＯＤ及ＮＯ 水平的影响。用药７ ｄ 组与自然戒断组比较（ｔ检验），ＭＴ２５、７５ ｍ ｇ／（ｋｇ·ｄ）两组的ＮＯ 水平明显高于对照组（Ｐ＜ ０．０５），ＭＴ１２５ ｍ ｇ／（ｋｇ·ｄ）组则有非常显著的差异（Ｐ＜ ０．００１），美沙酮组与对照组比较无统计学差异。以上各组ＳＯＤ 水平与对照组比较均无统计学意义。ＭＴ 长期用药组与单用海洛因组比较，其ＮＯ、ＳＯＤ水平均明显升高（Ｐ＜ ０．００１）。 The three doses of MTL (25,75,125 m g / (kg · d)] and two doses of methadone [2,4 m g / (kg · d)] and MT long-term protection Medication and other methods, according to the dose escalation method of heroin dependent rats blood SOD and NO levels. Compared with the natural withdrawal group (t test), the levels of NO in the MT 25,75 m g / (kg · d) group were significantly higher than those in the control group (P <0.05) There was a significant difference between group d and group d (P <0.001). There was no significant difference between the group of methadone and the control group. SOD levels in the above groups compared with the control group were not statistically significant. MT long-term drug group compared with heroin alone, the NO, SOD levels were significantly higher (P <0.001).