Researchers block a pain pathway in the brain.


In an opensource study published in the journal Brain, Saint Louis University researchers, the National Institutes of Health (NIH) and other academic institutions have discovered a way to block a pain pathway in animal models of chronic neuropathic pain including pain caused by chemotherapeutic agents and bone cancer pain suggesting a promising new approach to pain relief.

The team demonstrated that turning on a receptor in the brain and spinal cord counteracts chronic nerve pain in male and female rodents. Activating the A3 receptor, either by its native chemical stimulator, the small molecule adenosine, or by powerful synthetic small molecule drugs invented at the NIH, prevents or reverses pain that develops slowly from nerve damage without causing analgesic tolerance or intrinsic reward (unlike opioids).

Pain is an enormous problem. As an unmet medical need, pain causes suffering and comes with a multi-billion dollar societal cost. Current treatments are problematic because they cause intolerable side effects, diminish quality of life and do not sufficiently quell pain.

The most successful pharmacological approaches for the treatment of chronic pain rely on certain ‘pathways’, circuits involving opioid, adrenergic, and calcium channels.

For the past decade, scientists have tried to take advantage of these known pathways, the series of interactions between molecular-level components that lead to pain. While adenosine had shown potential for pain-killing in humans, researchers had not yet successfully leveraged this particular pain pathway because the targeted receptors engaged many side effects.

The current study demonstrated that activation of the A3 adenosine receptor subtype is key in mediating the pain relieving effects of adenosine.

It has long been appreciated that harnessing the potent pain-killing effects of adenosine could provide a breakthrough step towards an effective treatment for chronic pain. The findings suggest that this goal may be achieved by focusing future work on the A3AR pathway, in particular, as its activation provides robust pain reduction across several types of pain.

Researchers are excited to note that A3AR agonists are already in advanced clinical trials as anti-inflammatory and anticancer agents and show good safety profiles.

These studies suggest that A3AR activation by highly selective small molecular weight A3AR agonists such as MRS5698 activates a pain-reducing pathway supporting the idea that we could develop A3AR agonists as possible new therapeutics to treat chronic pain.

Source:  Saint Louis University 

 

Schematic representation of mechanisms underlying A3AR-induced anti-nociception revealed in our study. Data are mean ± SD.  Endogenous adenosine A3 receptor activation selectively alleviates persistent pain states.  Salvemini et al 2014.

Schematic representation of mechanisms underlying A3AR-induced anti-nociception revealed in our study. Data are mean ± SD. Endogenous adenosine A3 receptor activation selectively alleviates persistent pain states. Salvemini et al 2014.

2 comments

  • Richard Raymond

    I would like your permission to use the figure for a manuscript we plan to submit which deals with pain during arthritis. What would be the reference format for this report. Thank you

    Dr Richard Raymond

    Like

  • Thank you for your request. We did not create this artwork so cannot legally give permission for its use. Please find the link for the original whitepaper attached which contains the original diagram with description: https://academic.oup.com/brain/article/138/1/28/340784/Endogenous-adenosine-A3-receptor-activation

    Good luck with your manuscript.

    -Healthinnovations

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.