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	Wanna get High? Go Bike, Run
	19 Авг 2004	рейтинг (-7/13)
		просмотрено (812)
A research team has found very high levels of a naturally occurring cannabinoid called anandamide in runners and cyclists who exercised at moderate intensity for an extended period. Anandamide produces effects similar to those of THC, the psychoactive constituent of marijuana, leading researchers to speculate that "runner's high" may not be caused by endorphins released by the human body – as previously thought — but by a naturally occurring cannabinoid high. "I was aware of the limitations of the endorphin theory for explaining the runner's high, and I thought that Dr. Dietrich's novel hypothesis fit well within recent endocannabinoid discoveries," said Professor Phil Sparling, co-director of the Exercise Physiology Lab and Dietrich's host at Tech.. "The body's ability to produce cannabinoids is currently an intense area of research", said Dietrich, who studied them as a visiting professor in Georgia Tech's School of Applied Physiology this past year. "Cannabinoids that are produced naturally by the body are called endocannabinoids," Dietrich said. "The body's endocannabinoid system has evolved primarily for pain modulation—that is, pain or stress activates the system naturally. This activation, in turn, helps the body to modulate the pain." What's wrong with the endorphin theory? "Everything," says Arne Dietrich, a behavioral neuroscience professor at Georgia State University. "The endorphin theory has only survived as a popular myth. In pharmacology, it's been dead a long time. Endorphins are peptides. The beta endorphin is a 31-amino acid chain, a molecule too large to get through the blood-brain barrier." The blood-brain barrier sequesters the brain from the general blood supply. "Endorphins have certain functions in the blood-temperature regulation, blood pressure, but nothing to do with feelings of well being," he said. "Anandamide is a weak compound that is quickly metabolized. And runner's high is really a feeling of well being, not a tripping, or LSD high," says Andrea Allan, an associate professor of neuroscience at The University of New Mexico. "We should use our language a little better." Beach runner "It is hard for us to distinguish between endorphins and cannabinoids. When you block endorphins, you do feel pain more. You can't exclude endorphins. Any intense exercise produces both cannabinoids and endorphins. But the high has to do with dopamine." "Releasing dopamine in a natural way, like listening to music or running, does not do the damage a drug does by short circuiting that path," Allan said. "You don't develop a tolerance because the brain doesn't adapt." The endocannabinoid system is not engaged by an elevated heart rate, Dietrich said, but by muscle tissue breaking down. He attributed the evolutionary cause of the system to activities like "running from lions, or searching for food for days. You had to have a system that would allow your body to undergo such stresses."
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