BY KRISTIN A. BARYN
SC Contributing Writer
While studying rats, University of Colorado Boulder researchers found that taking morphine to ease the pain after abdominal surgery could in fact prolong post-operative pain.
The length of time a patient suffers may double or triple.
Led by Peter Grace, CU-Boulder’s Department of Psychology and Neuroscience research team found that both the morphine and the surgery itself excited glial cells in the nervous system. This causes them to send out additional pain signals.
Located in the brain, glial cells provide physical and nutritional support for neurons, nerve cells that make up the nervous system. Neurons are responsible for transmitting sensory stimuli.
Scientists have known that morphine binds with certain neuron receptors to dull pain. However, they now know that morphine also binds to a receptor on glial cells in the brain. This receptor is called TLR4, toll-like receptor 4, and this activates natural immunity.
Binding to TLR4 causes the cells to become excited, intensifying the pain.
With the control group being drug-free rats, researchers administered morphine to other groups of rats both before and after surgery to study the effects.
The group given morphine prior to surgery, but not after, took six weeks to fully recover, while the control group only took two weeks.
In the second experiment, scientists treated rats for one week after surgery, and it took these rats four weeks to recover.
Researchers also paired morphine with an opiate blocking medication called (+)-naloxone. They discovered that when taken together, the medication eliminated the extended post-operative pain.
The researchers are striving to learn how morphine excites glial cells in order to generate a successful combination of drugs to combat post-operative pain without prolonging suffering.
Though it is natural to desire comfort after a surgical procedure, this new studies show that patients will suffer longer than necessary by using morphine.
Unless taken with a successful opiate blocker like (+)-naloxone, people are recommended to avoid the use of morphine altogether.
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