image: Chemical structure of (-)-naloxone and (+)-naloxone enantiomers. Ki of (-)-naloxone for antagonizing opioid receptors is in the 1 nM range whereas (+)-naloxone has a very low affinity for opioid receptors with a Ki of 10 000 nM (Iijima et al., 1978). view more
Credit: Anttila et al., <i>eNeuro</i> (2018)
The life-saving drug used to treat opioid overdose, naloxone, reduces brain inflammation in the aftermath of stroke in male rats. The preclinical research, published in eNeuro, lays the groundwork for developing the first drug to promote recovery from a leading cause of adult disability.
Naloxone has been used for decades to prevent death from drug overdose and has become widely used in recent years in response to the unrelenting opioid crisis. Although the therapeutic potential of naloxone in stroke has been explored, research in this area is limited to a few case studies from the 1980s and inconclusive clinical trials.
Brandon Harvey, Mikko Airavaara, and colleagues expand on this work by showing in a rat model of stroke that one week of treatment with naloxone, beginning one day after the stroke, tempered the brain's immune response in the first week and improved neurological function in the second week. A form of naloxone that has limited interaction with opioid receptors had similar effects as the one used in overdose treatment, which may circumvent the side effects of activating the opioid system. As with the naloxone nasal spray Narcan, the researchers administered the drug to rats though the nose at doses similar to those that have been shown to be safe in humans. Together, these initial findings warrant further study of naloxone in different populations of animals and over a longer recovery period to investigate its potential for promoting recovery from stroke in humans.
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Article: Post-stroke intranasal (+)-naloxone delivery reduces microglial activation and improves behavioral recovery from ischemic injury
DOI: https://doi.org/10.1523/ENEURO.0395-17.2018
Corresponding authors: Brandon K. Harvey (National Institute on Drug Abuse, Baltimore, MD, USA), bharvey@intra.nida.nih.gov and Mikko Airavaara (University of Helsinki, Finland), mikko.airavaara@helsinki.fi
About eNeuro
eNeuro, the Society for Neuroscience's new open-access journal launched in 2014, publishes rigorous neuroscience research with double-blind peer review that masks the identity of both the authors and reviewers, minimizing the potential for implicit biases. eNeuro is distinguished by a broader scope and balanced perspective achieved by publishing negative results, failure to replicate or replication studies. New research, computational neuroscience, theories and methods are also published.
About The Society for Neuroscience
The Society for Neuroscience is the world's largest organization of scientists and physicians devoted to understanding the brain and nervous system. The nonprofit organization, founded in 1969, now has nearly 37,000 members in more than 90 countries and over 130 chapters worldwide.
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eNeuro