Researchers find how venom from marine cone snails reduces pain.
The study could help millions of people who suffer from neuropathic pain, which occurs due to damage of the nerve-system. Research has shown that disruption in signals between neurons is responsible for the chronic pain. Transmission of signals depends on several types of voltage-gated calcium channels (VGCCs). However, targeting these channels using available drugs can cause significant damage to the nervous system.
In the present study, researchers found that the toxin in snail venom reduces pain through indirect inhibition of R-type (Cav2.3), according to a news release.
Several scientists are trying to find a cure for neuropathic pain using chemicals produced by organisms. Snakes and spiders have been popular candidates for pain-drug research. However, humble marine cone snails aren't too far behind.
Research has shown that peptides called conotoxins from the venom of the snails can reduce pain in mammals. According to estimates, some 600 species of cone snails make as many as 100,000 different types of conotoxins. These toxins are simple proteins, containing few amino acids.
A new study, published in the Journal of General Physiology, describes one possible mechanism by which one conotoxin, Vc1.1, can alleviate pain.
Understanding the mechanism behind the snail's ability to cure pain could lead to development of new types of drugs.
David Adams and colleagues from RMIT University in Melbourne have previously shown that Vc1.1 works by acting through GABA type B (GABAB) to inhibit N-type (Cav2.2) channels.
The latest study shows that the venom peptide also acts through GABAB receptors to control the levels of another type of neuronal VGCCs. This class of VGCCs called R-type (Cav2.3) channels is associated with pain, but researchers aren't sure how it affects neuronal signaling.
Recently, researchers at the University of Queensland and colleagues had extracted a drug from snail venom. The team had said that the new drug was more potent morphine. ''It's a very exciting discovery which has the potential to be a blueprint for other protein-based medication," said David Craik, lead researcher and professor of biomolecular structure at the University of Queensland, to smh.com.