Scientists claim to have made a major discovery that could lead to more effective treatment of severe pain using morphine — an important pain relief drug.
Use of morphine can lead to a range of side-effects such as patients developing tolerance to morphine and increased sensitivity to pain. Until now,how this occurs has remained a mystery.
Now,an team from the University of Colorado in the US and the University of Adelaide in Australia has shown for the first time how opioid drugs,such as morphine,create an inflammatory response in the brain — by activating an immune receptor in the brain.
They have also demonstrated how this brain immune receptor can be blocked,laying the groundwork for the development of new therapeutic drugs that improve the effectiveness of morphine while reducing many of its problematic side effects.
Because morphine is considered to be such an important drug in the management of moderate to severe pain in patients right around the world,we believe these results will have far-reaching benefits, said lead author Dr Mark Hutchinson.
The team conducted studies in mice to validate the work done at the University of Colorado by the teams of Professor Hubert Yin and Professor Linda Watkins.
For some time it’s been assumed that the inflammatory response from morphine was being caused via the classical opioid receptors.
We,however,found instead that morphine binds to an immune receptor complex called toll-like receptor 4 (TLR4),and importantly this occurs in a very similar way to how this receptor detects bacteria.
Our experiments in mice have shown that if this relationship with the immune receptor is disrupted,it will prevent the inflammatory response.
This is an exciting result because it opens up possibilities for future drugs that promote the beneficial actions of morphine while negating some of the harmful side effects. This could lead to major advances in patient and palliative care, Prof Hutchinson said.
The findings have been published in the ‘Proceedings of the National Academy of Sciences’ journal.