Effect of nicotine administration on physical and psychological signs of withdrawal syndrome induced by single or repeated doses of morphine in rat

Background and Morphine addiction and morphine withdrawal syndrome are of main problems in human societies. In the present study، effect of nicotine on the strength of physical and psychological dependency، produced by single and repeated doses of morphine، was investigated. Male wistar rats were dependent to morphine with single and repeated dose protocols. In the single dose protocol، rats received only one dose of morphine and 24h later were given Naloxone. In the repeated dose protocol، rats received incremental doses of morphine for 7 days and 24h after the last dose (8th day) were given Naloxone. In the single dose protocol، rats were given one dose of nicotine 30 min before Naloxone. However in the repeated doses they received nicotine 15 min before morphine for 4 days from 4th day to 7th day. 5 min after Naloxone each rat′s behavior was captured for 30 min. then physical and psychological signs of withdrawal syndrome were recorded. Results showed that injection of repeated and even single dose of morphine can produce dependency. Nicotine consumption attenuated strength of withdrawal syndrome signs، specially increasing weight excrement and total withdrawal score in single dose protocol and weight excrement increasing، weight decreasing، place aversion، and total withdrawal score in repeated dose treatment. Based on our data، even a single dose of morphine can produce dependency in rats. Conversely، Nicotine consumption attenuates strength of withdrawal syndrome signs.