Peripheral involvement in nicotine-induced enhancement of ethanol intake

Alcohol. 2000 May;21(1):37-47. doi: 10.1016/s0741-8329(99)00099-3.

Abstract

It is a well-known fact that a large percentage of alcoholics smoke, and in the experimental rat, intermittent nicotine administration enhances ethanol intake and ethanol preference in a free-choice situation between 6% (v/v) ethanol and water. The present study focuses on the possible involvement of central and/or peripheral nicotine acetylcholine receptors (nAChR) in nicotine-induced sensitization to dopamine-related behavioral effects of ethanol. Wistar rats drinking less than 60% of their total daily fluid from a 6% ethanol solution were used in the study. Nicotine, vehicle, mecamylamine, hexamethonium, mecamylamine+nicotine, and hexamethonium+nicotine were administered subchronically for 15 days. All groups, except the vehicle pre-treated group, markedly increased their ethanol preference to approximately 80%, as well as their ethanol intake. NMRI mice received the same treatments for 10 days, after which ethanol (2.5 g/kg, intraperitoneal (i.p.)) was given acutely and locomotor activity was recorded. Ethanol-induced locomotor stimulation was enhanced in most groups, as compared to the vehicle pre-treated group. Administration of quarternary autonomic drugs to ethanol high-preferring rats (hexamethonium, methscopolamine, sotalol and phentolamine) according to different acute and chronic treatment protocols indicated that the enhanced ethanol intake may involve increased ganglionic and/or peripheral muscarinic neurotransmission. Taken together, the above results indicate that peripheral mechanisms may be involved in the enhancement of dopamine-related behavioral effects of ethanol observed after subchronic intermittent treatment with nicotinic drugs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Drinking*
  • Animals
  • Drinking / drug effects
  • Male
  • Mice
  • Motor Activity / drug effects*
  • Nicotine / pharmacology*
  • Nicotinic Agonists / pharmacology*
  • Nicotinic Antagonists / pharmacology
  • Rats
  • Rats, Wistar
  • Receptors, Nicotinic / drug effects*
  • Receptors, Nicotinic / physiology

Substances

  • Nicotinic Agonists
  • Nicotinic Antagonists
  • Receptors, Nicotinic
  • Nicotine