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20 



Public Hiilth Servic* { ^y 

 DEPARTMENT OF HEALTH & HUMAN SIRVICES Natioml Iniiituie* of HMrtV — ^ 



National Inatilule on Drug Atxjta 

 SeOO Flthsri Lina 

 4PR18 8M Rockvilla, Maryland 20687 



The Honorable Henry A. Waxman 

 Chairman, Subcommittee on 



Health and the Environment 

 Committee on Energy and Commerce 

 House of Representative! 

 Washington. D.C. 20515-6118 



Dear Mr. Waxman: 



I am writing in response to your request of April 1 1 for the evaluation by the National 

 Institute on Drug Abuse (NIDA) of the significance of the findings presented in 

 Dr. Victor DeNoble's 1983 research paper, 'Nicotine as a Positive Rcinforcer in Rats: 

 Effects of Infusion Dose and Fixed Ratio Size." The findings from Dr. DeNoble's study 

 demonstrate that nicotine does act in a reinforcing manner when tested in an animal model. 



It is also important to note that the rate of nicotine self-administration varied with the dose of 

 the drug. Furthermore, when the subject's baseline nicotine level was increased by the 

 researcher, the rate of self-administration of nicotine by the subject in the study was 

 decreased. These two findings support the contention that nicotine reinforcement was due to 

 the pharmacologic effects of this substance. These findings from the DeNoble study indicate 

 that nicotine has reinforcing properties, one of the hallmark characteristics of an addictive 

 drug, and arc consistent with those of NIDA-Supported researchers who have studied the 

 reinforcing effects of nicotine. 



You also requested my comments on the statement by the Phillip Moms Company that the 

 DeNoble study shows that 'nicotine is a reinforcer in the class of nonaddictivc chemical 

 compounds such as saccharin or water.' It Is true that saccharin and water can also serve as 

 reinforcers; however, the reinforcing propwties of water depend upon the animals being 

 deprived of water and the reinforcing pn^jcrties of saccharin are due to its taste. In the 

 DeNoble study, the animals were neither food nor water deprived, and nicotine was 

 administered intravenously, which avoids taste effects. Therefore, nicotine docs not have the 

 same characteristics a.s water and saccharin. 



I hope you will find this information helpful. 



Sincerely, 



Alan 1. Leshner, Ph.D. 

 Director 



