Rats self-administer sufentanil in aerosol form.
An ultrasonic nebulizer was used to create a drug vapor to develop an animal model for the self-administration of inhaled nonvolatile psychoactive drugs. An aerosol mist of a sufentanil citrate solution (10, 25, 50, or 75 micrograms/ml) was delivered to rats in response to lever presses on an FR 5 schedule of reinforcement. The speed of acquisition of the operant response and the selectivity of the drug effect were examined. Rats given access to sufentanil vapor (50 or 75 micrograms/ml) in 13-15 h overnight training sessions reached an average of one reinforcement per hour on an FR 5 schedule of reinforcement significantly sooner than did rats given access to water vapor. Responding maintained by sufentanil during 2-h daily testing sessions was dose dependent at 25, 50, and 75 micrograms/ml. Substituting water vapor for each of the four sufentanil concentrations significantly reduced responding within 5-20 sessions. Naloxone (1 mg/kg, IP) decreased responding for sufentanil to the level attained under water vapor. Presentation of drugs in aerosol form thus provides reasonable means of demonstrating in animals the reinforcing properties of non-volatile drugs by the pulmonary or intranasal route.
Jaffe
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AB
Addiction Research Center, National Institute on Drug Abuse, Baltimore, MD 21224.
Sharpe
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LG
Jaffe
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JH
D000336:Aerosols; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects; D005283:Fentanyl / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012055:Reinforcement Schedule; D012646:Self Administration; D017409:Sufentanil
D000336:Aerosols; D000701:Analgesics, Opioid; D009270:Naloxone; D017409:Sufentanil; D005283:Fentanyl