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A new study shows, for the first
time, that the release of the body’s own marijuana-like compounds is
crucial to stress-induced analgesia – the body’s way of initially
shielding pain after a serious injury.
The work, led by scientists at UGA and the University of California, Irvine,
may yield a target for new drug therapies that will completely bypass the current
arguments over the use of medical marijuana. In theory, the new research makes
it possible to design a pill that will have the same pain relieving effects
as smoked marijuana, but through an indirect mechanism that could also reduce
unwanted psychoactive side effects and not have the same political baggage.
“There is no prescription or over the counter drug that allows us to
manipulate the level of the brain’s marijuana-like compounds,” said
Andrea Hohmann, a neuroscientist in the department of psychology at the University
of Georgia and co-author of the paper. “This is the first time anyone
has shown that one of the body’s naturally occurring cannabinoids, a
compound known as 2-AG, has anything to do with pain regulation under natural
conditions.”
The study was published in the journal Nature.
Hohmann’s co-author, Daniele Piomelli at the University of California-Irvine,
is the discoverer of a compound that blocks the breakdown of this marijuana-like
compound called 2-AG, and it is that blocking compound, patented by UC-Irvine,
that could become the new drug of choice for those suffering from pain or stress
conditions. Importantly, it would not require people to smoke marijuana to
obtain relief or wrestle with the legal issues surrounding the drug.
Others from UGA involved in the study include faculty members Philip Holmes
and Jonathon Crystal and students Richard Suplita, Nathan Bolton and Mark Neely.
Scientists have long known that injured athletes or even gunshot victims have
a period of time in which the body’s pain reaction is delayed. This effect
is called “stress-induced analgesia.” By the mid-1990s, researchers
had targeted the sites of action of the brain’s naturally occurring marijuana-like
compounds as having a crucial role in blocking pain, but no one understood
the conditions in which these compounds were released to block pain.
Researchers along the way found out there are two kinds of stress-induced
analgesia mechanisms, opioid and nonopioid (or “opioid independent”).
Hohmann and colleagues discovered that the opioid-independent form was produced
by release of the brain’s own marijuana-like compounds.
“We showed that cannabinoid receptors were involved in this remarkable
phenomenon,” said Hohmann, “because blocking the receptors where
marijuana acts virtually erased this opioid-independent form of stress analgesia.”
A drug derived from the new research would likely be more effective and specific
than smoked marijuana, said Hohmann. |
Andrea
Hohmann, a neuroscientist in UGA’s psychology department, and her colleagues
were able to prove that a connection exists between pain suppression and the
release of marijuana-like compounds produced by the brain.
