EDITOR'S NOTE: Recently, a house committee approved a ban on ephedrine. The drug was linked to the death of an Illinois high school athlete and may have been involved in the death of a major league pitching prospect. Miller is an expert on ephedrine and can comment about its effects on the body.
Nicotine and ephedrine have a powerful effect on the human brain and body. Medical researchers know that in addition to creating feelings of euphoria, the two addictive and widely used drugs also suppress weight. Dennis Miller, a neuropharmacologist at the University of Missouri-Columbia, uses this knowledge to investigate whether scientists can produce a safer diet pill.
Miller's research focuses on the relationship between human behavior and the chemical processes within the human brain. He emphasizes that human behavior derives from the communication among neurons within the complex organ. This communication is made possible by neurotransmitter, the scientific name for chemicals that are released from one neuron and activate or deactivate a nearby neuron.
Many drugs alter brain function and behavior by increasing or decreasing the amount of neurotransmitter that is available to communicate with nearby neurons. Different drugs use different mechanisms to increase or decrease the amount of neurotransmitter. For example, the success of many weight-reducing drugs, such as ephedrine, is related to their ability to alter natural brain functions that normally decrease the amount of neurotransmitter. In other words, drugs that cause weight loss increase the amount of neurotransmitter that can interact with nearby neurons.
Nicotine, the agent in tobacco believed to be responsible for smoking addiction, also increases the amount of neurotransmitter. However, rather than causing neurotransmitter to recycle through neurons, nicotine activates "nicotinic" receptors. This activation simply leads to more neurotransmitter being released without being recycled. Thus, weight-loss drugs and nicotine increase the amount of neurotransmitter that is available, and in many cases produce similar behaviors. One such behavior caused by weight-loss drugs and nicotine is the ability to increase metabolism and decrease food intake.
Of course, Miller and his colleagues do not recommend smoking as means to control one's weight. Ephedrine also has harmful side effects. It activates pathways in the human brain that are responsible for weight loss, but it also activates pathways that could lead to dramatic change in heart rate or blood pressure. Moreover, ephedrine, like nicotine, produces a "high" and can be addictive.
Miller and his colleagues are investigating the power of nicotinic receptors as a therapeutic target for new weight-loss drugs that do not have harmful side effects. In this effort, they focus their research on determining the properties of ephedrine and nicotine individually on food consumption and neurotransmitter levels in the brain. They then will assess the drugs' interaction to find any commonalities. The ultimate goal is to isolate properties that may be responsible for decreasing food intake and increasing metabolism, as well as discovering the properties that are responsible for the harmful side effects. By experimenting with rats in a laboratory, researchers could develop new drugs that incorporate the "beneficial" effects of nicotine and ephedrine without the harmful side effects.
"Right now, our research is kind of a fishing expedition," Miller says. "We've started with ephedrine. We have decent idea how it works in the brain. Now we're trying to concentrate on how it interacts with nicotine and other targets in the brain."
Miller does not advocate people relying solely on a diet pill to lose weight, but he acknowledges that some people need help beyond exercise and a healthy diet. His research is a pilot project sponsored by the MU Research Council.
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