Would you want to live your entire life without feeling any pain? Thanks to a rare genetic defect, a few lucky people — or unlucky, depending on your perspective — do not know what it’s like to feel an injury because their bodies lack the ability to feel pain. University College London (UCL) scientists have discovered a way to harness that defect to potentially create a pain free reality for everyone else.
Nine years ago, in a study of those with the genetic defect, it was determined that sodium channel Nav1.7 was necessary for the body to signal pain pathways. Those born with the defect have non-functioning Nav1.7 and therefore they don’t feel pain.
In the more recent UCL study, researchers were able to formulate what is essentially a recipe for painlessness using genetically modified mice. Humans and mice that lack Nav1.7 are also known to produce high levels of natural opioid peptides, so the researchers gave the mice without Nav1.7 an opioid blocker, nalaxone, to see if it would enable them to feel pain like normal. It did.
Following the mice trials, nalaxone was then provided to a 39-year-old woman with the genetic defect who had never felt pain before, and the result was the same. She was, for the first time in her life, able to know what it was like to hurt.
After ten years of research, it was the first meaningful discovery scientists have found involving a link between Nav1.7 and human pain, according to Professor John Wood of UCL Medicine.
After a decade of rather disappointing drug trials, we now have confirmation that Nav1.7 really is a key element in human pain.
“The secret ingredient turned out to be good old-fashioned opioid peptides”, he explained.
Wood says that UCL has filed a patent involving the combination of low dose opioids with Nav1.7 blockers, which should replicate the genetic defect in humans. “We have already successfully tested this approach in unmodified mice”, he said.
According to Business Standard, broad-spectrum sodium channel blockers have been used as local anesthetics in the past, but unlike those with the genetic mutation where the only only side-effect is the inability to smell, the anesthetics cause complete numbness and other more serious long-term side-effects when overused.
While opiates such as morphine are well-known to reduce pain, they are not only known to be highly addictive, but also cause a tolerance build-up in the user. “Used in combination with Nav1.7 blockers, the dose of opioid needed to prevent pain is very low”, said Wood.
The drug, which researchers hope to begin testing on human in 2017, could create the world’s first powerful painkiller without carrying a risk of addiction.
