Northwestern Study Finds Possible Link Between Alcoholism, Smoking

November 06, 1996

CHICAGO --- Striking new biochemical evidence that shows a link between alcoholism and nicotine addiction has been discovered by pharmacologists at Northwestern University Medical School.

Northwestern researchers reported that alcoholic beverages modify the activity of a neuronal nicotinic receptor -- the same target site in the nervous system that is altered by exposure to the nicotine in tobacco.

The study, published in the October 18 issue of the journal Neuroscience Letters, may help explain the high correlation between alcoholism and smoking. Although about 10 percent of the population are heavy smokers, other research shows that among alcoholics, 70 to 90 percent are heavy smokers.

One reason for this connection is that nicotine stimulates and then desensitizes the neuronal nicotinic acetylcholine receptor, according to Toshio Narahashi, who headed the study. Narahashi is the John Evans Professor of Pharmacology and the Alfred Newton Richards Professor at Northwestern University Medical School.

Narahashi and his colleagues showed that low concentrations of nicotine applied over a prolonged period desensitized the acetylcholine receptor without stimulating it.

"The acetylcholine receptor of the nicotine addict may be slightly desensitized, meaning that higher doses of alcohol are required to stimulate it," Narahashi said. More experiments must be done to prove this hypothesis, he said.

The researchers also found that alcohol affects the acetylcholine receptors at minute concentrations -- much lower than those reported for its other target sites in the nervous system.

"The potent action of alcohol on the neuronal nicotinic acetylcholine receptors suggests that alcohol and nicotine interact at this site. Our findings may also shed new light on the molecular mechanism of action of alcohol," Narahashi said.

Acetylcholine is a neurotransmitter, or chemical messenger, that affects a number of body systems, including the cardiovascular, gastrointestinal, urinary and respiratory systems. Receptors are usually protein molecules, either on or within a cell, that bind with neurotransmitters or hormones and cause a basic change in the structure of the molecule.

Other investigators have identified several sites for alcohol among various targets, i.e., neuroreceptors and ion channels, the tiny "pores" that promote or inhibit passage of sodium, calcium, potassium or chloride in and out of the cell membrane. However, alcohol's exact molecular mechanism of action on the nervous system remains controversial.

Narahashi noted that alcohol does act on a number of other target sites, but at high concentrations. This implies that the function of these channel systems is altered more in the later stages of alcohol intoxication, he said.

"The question thus arises as to what systems and mechanisms in the central nervous system are altered in the earlier stages of alcohol intoxication when the blood-alcohol concentrations are much lower, yet are sufficient to modify behavioral traits such as mood, attention and craving," he said.

Using cell models that contain ion channels and membrane receptors similar to those in humans and also release acetylcholine, Narahashi and his colleagues found that alcohol modified the kinetics of the neuronal nicotinic acetylcholine receptors at concentrations as low as 30 to 100 micromoles per liter, or at a potency 1,000 times higher than that for the other receptors and channels.

Their results suggest that neuronal nicotinic acetylcholine receptors may be important target sites of alcohol, particularly in the early stages of alcohol intoxication.

Another important point, Narahashi said, is that there are several subtypes of the neuronal nicotinic acetylcholine receptor that make up different combinations of receptor subunits. These subtypes are known to show various sensitivities to several drugs and play a number of physiological roles in the brain.

"It is likely that alcohol at low (micromolar) concentrations acts on a specific subtype or subtypes of acetylcholine receptor," he said.

Narahashi and his colleagues are now pursuing this line of research in the laboratory.

Narahashi's co-researchers on this study were Keiichi Nagata, Gary L. Aistrup, Chao-Sheng Huang, William Marszalec, and Jin-Ho Song, of the department of molecular pharmacology and biological chemistry, and Jay Z. Yeh, professor of molecular pharmacology and biological chemistry and of anesthesiology at Northwestern University Medical School.

Northwestern University

Related Alcohol Articles from Brightsurf:

Alcohol use changed right after COVID-19 lockdown
One in four adults reported a change in alcohol use almost immediately after stay-at-home orders were issued: 14% reported drinking more alcohol and reported higher levels of stress and anxiety than those who did not drink and those whose use stayed the same.

Changes in hospitalizations for alcohol use disorder in US
Changes over nearly two decades in the rate of hospitalizations and in-hospital deaths from alcohol use disorder in the US were examined in this study.

Associations of alcohol consumption, alcohol-induced passing out with risk of dementia
The risk of future dementia associated with overall alcohol consumption and alcohol-induced loss of consciousness in a population of current drinkers was examined in this observational study with more than 131,000 adults.

New alcohol genes uncovered
Do you have what is known as problematic alcohol use?

Does estrogen influence alcohol use disorder?
A new study from researchers at the University of Illinois at Chicago shows that high estrogen levels may make alcohol more rewarding to female mice.

Sobering new data on drinking and driving: 15% of US alcohol-related motor vehicle fatalities involve alcohol under the legal limit
A new study in the American Journal of Preventive Medicine, published by Elsevier, found that motor vehicle crashes involving drivers with blood alcohol concentrations (BACs) below the legal limit of 0.08 percent accounted for 15% of alcohol-involved crash deaths in the United States.

Alcohol-induced deaths in US
National vital statistics data from 2000 to 2016 were used to examine how rates of alcohol-induced deaths (defined as those deaths due to alcohol consumption that could be avoided if alcohol weren't involved) have changed in the US and to compare the results by demographic groups including sex, race/ethnicity, age, socioeconomic status and geographic location.

Cuts in alcohol duty linked to 2000 more alcohol-related deaths in England
Government cuts to alcohol taxes have had dramatic consequences for public health, including nearly 2000 more alcohol-related deaths in England since 2012, according to new research from the University of Sheffield's School of Health and Related Research (ScHARR).

Integrated stepped alcohol treatment for people in HIV care improves both HIV & alcohol outcomes
Increasing the intensity of treatment for alcohol use disorder (AUD) over time improves alcohol-related outcomes among people with HIV, according to new clinical research supported by the National Institutes of Health.

The Lancet:Targets to reduce harmful alcohol use are likely to be missed as global alcohol intake increases
Increasing rates of alcohol use suggest that the world is not on track to achieve targets against harmful alcohol use, according to a study of 189 countries' alcohol intake between 1990-2017 and estimated intake up to 2030, published in The Lancet.

Read More: Alcohol News and Alcohol Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to