NICOTINE ABSTINENCE SYNDROME PRECIPITATED BY AN ANALOG OF NEUROPEPTIDE FF

In a recently introduced rodent model of nicotine abstinence syndrome the observed behavioral signs closely resembled those typical of rat o piate abstinence syndrome. Nicotine-induced release of endogenous opio ids may contribute to nicotine dependence; morphine potently reverses nicotine abstinence signs, while naloxone precipitates abstinence sign s and prevents nicotine from alleviating them. Considerable evidence s uggests that neuropeptide FF, an endogenous antiopiate peptide, contri butes to opiate dependence. Third ventricle injection of neuropeptide FF precipitates abstinence syndrome in morphine-dependent rats, as doe s SC injection of its lipophilic analogs, dansyl-PQRFamide and dansyl- RFamide. Might NPFF also play a role in nicotine dependence? In the pr esent study, SC injection of 15 or 25 mg/kg dansyl-RFamide or vehicle alone dose dependently precipitated an abstinence syndrome in nicotine -dependent rats. There was a significant, p < 0.01, positive linear tr end of abstinence signs as a function of dose. Categories of abstinenc e signs had the same rank ordering by frequency as observed in spontan eous nicotine abstinence. Injection of 25 mg/kg dansyl-RFamide SC had no significant effect in nondependent rats.