original abstract†Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
Delayed onset muscle soreness (DOMS) is reduced when the same exercise is repeated after a certain interval. However, the mechanism for this adaptation, called a repeated bout effect, is still not well understood. Recently, we showed that upregulated nerve growth factor (NGF) triggered by B2 bradykinin receptor (B2R) activation in exercised muscle was responsible for DOMS. In this study, we investigated whether NGF upregulation was reduced after repeated bouts of exercise in rats, and if so, whether this change occurred upstream of B2R. A bout of 500 lengthening contractions (LC) was applied on day 0 and again 5 days later. DOMS was evaluated by the mechanical withdrawal threshold of the exercised extensor digitorum longus (EDL) muscle. Mechanical hyperalgesia and NGF mRNA upregulation in EDL were observed after the first LC, but not after the second LC. We then injected HOE140, a B2R antagonist with effects lasting only several hours, once before the first LC. This blocked the development of mechanical hyperalgesia and NGF mRNA upregulation not only after the first LC but also after the second LC. This suggests that adaptation occurred upstream of B2R, as the influence of the first LC was limited to that area by HOE140.
- “Bradykinin and nerve growth factor play pivotal roles in muscular mechanical hyperalgesia after exercise (delayed-onset muscle soreness),” an article in J Neurosci, 2010.
- “Upregulated glial cell line-derived neurotrophic factor through cyclooxygenase-2 activation in the muscle is required for mechanical hyperalgesia after exercise in rats,” an article in Journal of Physiology, 2013.
- “Delayed onset muscle soreness: Involvement of neurotrophic factors,” an article in J Physiol Sci, 2016.
These two articles on PainScience.com cite Urai 2013 as a source:
- PS Post-Exercise, Delayed-Onset Muscle Soreness — The biology & treatment of “muscle fever,” the deep muscle soreness that surges 24-48 hours after an unfamiliar workout intensity
- PS Massage Does Not Reduce Inflammation — The making of a new massage myth from a high-tech study of muscle samples after intense exercise
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- A Bayesian model-averaged meta-analysis of the power pose effect with informed and default priors: the case of felt power. Gronau 2017 Comprehensive Results in Social Psychology.
- Association of Spinal Manipulative Therapy With Clinical Benefit and Harm for Acute Low Back Pain: Systematic Review and Meta-analysis. Paige 2017 JAMA.
- Incidence of Spontaneous Resorption of Lumbar Disc Herniation: A Meta-Analysis. Zhong 2017 Pain Physician.
- How much is too much? (Part 1) International Olympic Committee consensus statement on load in sport and risk of injury. Soligard 2016 Br J Sports Med.
- Chiropractic spinal manipulative therapy for migraine: a three-armed, single-blinded, placebo, randomized controlled trial. Chaibi 2016 Eur J Neurol.