Nicotine treatment 'could control obesity'

Scientists have identified a group of neurons in the brain responsible for smokers' lack of appetite. In an article in the journal Science, Yale University researchers describe experiments on mice which found nicotine activates neurons to send signals the body has had enough to eat. However they are not the same neurons which trigger a craving for tobacco. As a result, the researchers say nicotine-based treatments could help control obesity. A research team from Yale University School of Medicine and Baylor College of Medicine in Houston performed a combination of molecular, pharmacological, behavioural and genetic experiments on mice. They found that nicotine influences a collection of central nervous system circuits, known as the body's hypothalamic melanocortin system, by activating certain receptors. These receptors, in turn, increase the activity of pro-opiomelanocortin (POMC) neurons, known for their effects on obesity in humans and animals

Why smoking may increase heart risk

"U.S. researchers suggest nicotine may be a reason smoking increases the risk of cardiovascular diseases. Charles Drew University of Medicine and Science in Los Angeles and Western University of Health Sciences in Pomona, Calif., said the studies in animals found nicotine promotes insulin resistance - a prediabetic condition where blood-sugar levels are above normal. Other studies show people with prediabetes are at greater risk of developing stroke, heart attack and other cardiovascular diseases. The researchers studied the effects of twice-daily injections of nicotine on 24 adult mice during a two-week period. "Our results in mice show that nicotine administration leads to both weight loss and decreased food intake," study researcher Theodore Friedman of Charles Drew University said in a statement. "Mice exposed to nicotine have less fat. In spite of this, mice have abnormal glucose tolerance and are insulin resistant." In the tests, the mice receiving nicotine also had high levels of the stress hormone cortisol, which increases blood pressure and blood sugar. "Our results suggest that decreasing insulin resistance may reduce the heart disease seen in smokers," Friedman said. The study was presented at The Endocrine Society's 91st annual meeting in Washington" - UPI

Nicotine may have more profound impact than previously thought

"Nicotine isn't just addictive. It may also interfere with dozens of cellular interactions in the body, new Brown University research suggests. Conversely, the data could also help scientists develop better treatments for various diseases. Pharmaceutical companies rely on basic research to identify new cellular interactions that can, in turn, serve as targets for potential new drugs. "It opens several new lines of investigation," said lead author Edward Hawrot, professor of molecular science, molecular pharmacology, physiology and biotechnology at Brown University. Hawrot's research is highlighted in a paper published April 3 in the Journal of Proteome Research. He and a team that included graduate students William Brucker and Joao Paulo set out to provide a more basic understanding of how nicotine affects the process of cell communication through the mammalian nervous system" - EurekAlert

Potential drug therapy for quitting smoking

"Researchers have uncovered information that may lead to a new medical treatment for nicotine addiction. Cigarette smoking is one of the most widespread preventable causes of death and disease in developed countries. Annually, the habit is responsible for about 440,000 deaths and $160 billion in annual health-related costs nationwide. The neuropeptide hypocretin-1 (Orexin A) may start a series of reactions in the body that maintains tobacco addiction in smokers. Targeting the chemical could offer a potential treatment for smoking cessation. In rats, blocking hypocretin-1 receptors not only decreased their reliance on nicotine, it also eliminated the stimulatory effects nicotine had on the areas of the brain linked to rewards. 'This suggests that hypocretin-1 may play a major role in driving tobacco use in smokers to want more nicotine,' Paul Kenny, Ph.D., a research scientist at Scripps Florida, in Jupiter, Fla., was quoted as saying. 'If we can find a way to effectively block this receptor, it could mean a novel way to help break people's addiction to tobacco.' Quitting smoking has proven to be a difficult task. Despite years of health warnings against tobacco, only 10 percent of smokers who attempt to quit stay smoke-free after one year. Source: Proceedings of the National Academy of Sciences, published online November 24, 2008

Experts say new tobacco product targets young adults

"New research at West Virginia University is examining whether a smokeless, spitless tobacco product aimed at young adults is catching on. And the researchers have found that RJ Reynolds' Camel Snus - touted as a socially acceptable way to satisfy addiction - contains surprisingly high levels of nicotine. 'Camel Snus contains more nicotine than most other snuff products,' said Bruce Adkins of the state Division of Tobacco Prevention in Charleston. 'In fact, the Camel Snus currently being marketed in West Virginia contains double the nicotine of an earlier tested version sold elsewhere in the United States. This provides a new example of the tobacco companies' manipulating nicotine levels without informing consumers'" - newswise