Hunger and cigarettes: satiety receptors
Are you fighting with extra appetite? It is easier for smokers: this vicious habit - or rather, nicotine that enters the body - effectively suppresses hunger. And now, scientists were able to find out which receptors are responsible for this.
Receptor on which influences nicotine, when getting in our brain, represents quite big protein. It consists of several subunits, and in different combination these subunits can give different receptors with different functions. However, nicotine can connect with them in any case, causing entire cascade of further events, the specific set of which depends on the form of the protein. In one case it stimulates relaxation, in another - change of blood pressure, part of these reactions is responsible for smoking addiction.
One of these reactions - loss of appetite - is well-known. Scientists connect this effect with influence that nicotine has over the system of internal reinforcement - when launching it, cigarette becomes like a source of satisfaction, displacing from this role food. However new research has shown that it is not so.
Neurophysiologists that work in USA: Marina Picciotto, Yann Mineur and their colleagues have researched antidepressant effects that appear with mice when activating one specified form of nicotine receptor. On the mice has also showed up side effect: they haven't gain necessary weight. Scientists have shown that receptor that is related to nicotine passes "signal of satiety" that doesn't differ in anything from the signal that appears after eating a lot of food. Thanks to this effect mice during two hours after receptor activation ate twice less than animals of control group, but during one month of experiments quantity of fat accumulated by them has fallen by 15-20 %.
By the way, namely the risk of gaining extra weight often holds smokers from attempts to quit. With this connection Picciotto has assumed that if to continue pharmaceutical impact on receptor, first stages of smoking refusal will pass much easier. And, probably, such preparation will be effective generally for loss of appetite and weight for all who need it, no matter whether they smoke or not.
It is interesting that in some previous researches was shown difference in changes of the weight caused by nicotine consumption by mice dam or male. Males have bigger weight loss during "smoking", but, after "quitting" they gain weight quicker. What is the reason of this difference still has to be determined. In experiments of Picciotto's group were used only males, and, probably, authors will repeat them, including in experiments dams.