Tag Archives: exposure to nicotine

Cigarette Smoke Exposure Not Safe in Any Amount

Have you seen the recent new headline: Surgeon General Issues Latest Warning: Tobacco Smoke Exposure Not Safe in Any Amount?

Statistics highlight how one in five Americans are first-hand smokers. Whether these smokers have one cigarette a week, or an entire pack a day, the poisonous effects of cigarette smoke does not discriminate.

There are millions of others who are exposed to second-hand smoke, whether regularly or irregularly. These people are also at equal risk to the poisonous effects of tobacco smoke.

The Surgeon General stresses that no amount of cigarette smoke is safe for anyone.

Surgeon General’s Warning

For over 45 years the Surgeon General has been issuing strong warnings about the consequences of smoking and tobacco exposure. In the latest release, the Surgeon General warns against any and all exposure to tobacco smoke: whether a smoker or a second-hand bystander, no level of smoke is considered safe.

Social smokers often consider their habit “safer” because their exposure is limited to a cigarette here and there. Not so, claims the Surgeon General. Cigarette smoke immediately travels from the cigarette, into the lungs, and into the blood stream.

The toxins then attack the blood vessels, causing them to narrow, and even encourages clotting of the blood. This increases the person’s chance of heart attack or stroke.

Immediate Effects of Cigarette Smoke

There are numerous deadly effects of smoking on the body. Specific immediate effects pointed out by the Surgeon General include:

  • The blood pumped through the body carries the toxins from the tobacco to every organ, thus affecting every organ’s functioning.
  • The tobacco smoke’s toxins affect the body’s DNA, leading to different types of cancers.
  • The functions of the lungs are affected by the tobacco smoke’s poisons, leading to COPD.

While smoking for longer periods of time will increase the negative effects of smoking, no cigarette—not even one, and not even second-hand smoke—is a safe amount to be exposed to.

The Only Solution: Prevention

No matter how long a person has been smoking, quitting is the best thing that can be done to stop the poisoning and toxic effects of cigarettes on the body. Quitting at any stage gives your health a boost.

Reference: “Surgeon General: One Cigarette is One Too Many” by Lauran Neergaard
[http://www.huffingtonpost.com/2010/12/09/surgeon-general-1-cigaret_n_794250.html\

Two Nicotine Addiction Puzzles Explained

The stranglehold of nicotine addiction leads to more than four million smoking-related deaths each year. Scientists at the California Institute of Technology have now explained two roots of that addiction. The discoveries may offer new hope not just for smokers, but eventually also for sufferers of Parkinson’s disease, a debilitating movement disorder that affects some 40 million people worldwide.

Researchers have known for decades that chronic exposure to nicotine increases the number of nicotine receptors–molecules that are activated by binding to the drug–on nerve cells. The binding of nicotine to these receptors, and in particular to one specific subunit known as alpha4, enhances the release of a pleasure-causing neurotransmitter called dopamine.

But “this increase is confusing,” says Henry A. Lester, the Bren Professor of Biology at Caltech, “because for opioid addiction, and for many other classes of addictions and of drugs in general, the body attempts homeostasis and adjusts the number of receptors downward if there is a constant stimulus.” Understanding this paradox–how it is possible that smokers become tolerant to the pleasurable effects of nicotine despite the fact that their brains produce new nicotine receptors in response to the chemical–is crucial for defeating nicotine’s addictive power.

Lester, his postdoctoral researcher Raad Nashmi, and their colleagues at Caltech, the University of Colorado at Boulder, and the University of Pennsylvania School of Medicine, have now solved the mystery, by developing a special mouse strain with fluorescent nicotine receptors. These fluorescent tags allowed the scientists to monitor the effects of the nicotine throughout the brain, down to the level of individual neurons.

“We find that alpha4 containing receptors, those with some of the highest sensitivity to nicotine, are upregulated”–or increased in number–“by chronic nicotine in a cell-specific fashion,” Lester explains. “In particular, the alpha4-containing receptors are indeed upregulated in the dopamine-producing portions of the brain, but not in the dopamine neurons themselves.” Instead, the increase in receptor number occurs only in neurons that inhibit dopamine neurons–a group called the GABAergic neurons.

Dopamine FormulaThis surprising result led the researchers to conduct experiments with delicate electrical probes. In chronic nicotine-treated mice (and presumably in chronic smokers), the dopamine neurons are chronically inhibited from firing in the absence of nicotine. And nicotine itself still excites the dopamine neurons, leading to pleasure, but much less than expected.

“This research explains tolerance during nicotine addiction,” Lester says. “Once in a while, an important piece of a puzzle does fall into place.”

“This is outstanding work that will open the door to further studies of nicotinic receptor upregulation in the cognitive and rewarding effects of nicotine,” comments Daniel S. McGehee of the University of Chicago, who studies the neurobiology of nicotine addiction. McGehee was not involved in the present research.

But there’s more. In the special Caltech mice, the largest number of new nicotine receptors appeared in the mouse forebrain. This is the part of the brain involved in cognition. Electrical measurements showed that these new receptors also helped to boost synaptic transmission. The result may explain why many smokers claim that cigarettes actually help them think better–and why 44 percent of the cigarettes smoked in the United States are consumed by people with mental health problems.

“People may attempt to medicate themselves with nicotine, and my research is also aimed at trying to understand the mechanism behind that,” Lester says.

“We now think that we need to concentrate on drugs that manipulate upregulation.” Lester adds. His lab is currently developing simpler cell-based systems using the fluorescently labeled nicotine receptors. Using special microscopes, the effect of particular drugs on those receptors can be monitored.

One long-term benefit of the research could be the development of better therapies for Parkinson’s disease, the chronic neurological condition that gradually destr