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),” Shiori Murase, Etsuji Terazawa, Fernando Queme, Hiroki Ota, Teru Matsuda, Kenji Hirate, Yasuko Kozaki, Kimiaki Katanosaka, Toru Taguchi, Hisako Urai, and Kazue Mizumura, 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,” Shiori Murase, Etsuji Terazawa, Kenji Hirate, Hiroki Yamanaka, Hirosato Kanda, Koichi Noguchi, Hiroki Ota, Fernando Queme, Toru Taguchi, and Kazue Mizumura, Journal of Physiology, 2013.
- “Delayed onset muscle soreness: Involvement of neurotrophic factors,” Kazue Mizumura and Toru Taguchi, J Physiol Sci, 2016.
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:
- Relationships Between Sleep Quality and Pain-Related Factors for People with Chronic Low Back Pain: Tests of Reciprocal and Time of Day Effects. Gerhart 2017 Ann Behav Med.
- Modulation in the elastic properties of gastrocnemius muscle heads in individuals with plantar fasciitis and its relationship with pain. Zhou 2020 Sci Rep.
- Association Between Plantar Fasciitis and Isolated Gastrocnemius Tightness. Nakale 2018 Foot Ankle Int.
- No Added Benefit of Combining Dry Needling With Guideline-Based Physical Therapy When Managing Chronic Neck Pain: A Randomized Controlled Trial. Stieven 2020 J Orthop Sports Phys Ther.
- Effectiveness of customised foot orthoses for Achilles tendinopathy: a randomised controlled trial. Munteanu 2015 Br J Sports Med.