小剂量吗啡对大鼠活动性的影响

腹腔注射不同剂量吗啡，观察各组大鼠在给药后不同时间的活动性（ｌｏｃｏｍｏｔｏｒａｃｔｉｖｉｔｙ，ＬＡ），连续给药８天，每天给药后９５ｍｉｎ内，每间隔１５ｍｉｎ，记录大鼠５ｍｉｎ内在限定空间中所走格数。结果表明：随吗啡给药剂量或次数增加，ＬＡ呈升高趋势；使大鼠ＬＡ明显兴夯的适宜低剂量为４ｍｇ／ｋｇ／ｄａｙ，该剂量下每天药后１５－２０ｍｉｎＬＡ为峰值，而且此时段ＬＡ逐日升高，至第８日出现下降趋势，此毕

THE EFFECTS OF LOW DOSE MORPHINE ON LOCOMOTOR ACTIVITIES IN RATS

The locomotor achvities (LA) of rats were tested every 15 mins for 95 mins after morphine injected intraperitoneally with 8, 4, 2, 1mg/kg/day respectively once a day during the 8-day experiment,and the number of squares (10 X 10 cm2) which the rats passed by in 5 mins were recorded. Results showed that there were significant differences between the groups treared with 8 or 4mg/ kg / day of morphine and normal saline on day2-8, and between the groups with 2mg/kg/day of morphine and the control group on day2, 5 and 6. Thus 4mg / kg / day was the most suitable low dose of morphine for activating LA. The peak effect of 4mg/kg/day of morphine was at 15-20 mins after injection, and it kept going up for 8 days. It was suggested that low dose of morphine may be more stutable for related behavioral effects such as those of conditioned place preference or self-administration, and the best time course for training tasks may be within 20 min after the rats were exposed to morphine.