Journal of Pain Research (Oct 2019)
Effects Of Heat-Conduction Dry Needling Therapy On TRPV1 Channel In Rats
Abstract
Gang Wang, Xinglin Wang, Qian Gao, Ning Wang, Ming Zhou Department of Rehabilitation Medicine, First Medical Center of Chinese PLA General Hospital, Beijing 100853, People’s Republic of ChinaCorrespondence: Xinglin WangDepartment of Rehabilitation Medicine, First Medical Center of Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, People’s Republic of ChinaTel +86 10 6693 7555Email [email protected]: This study was aimed to investigate the effects of heat-conduction dry needling therapy on chronic myofascial pain syndrome (CMPS) in rats and explore the analgesic mechanisms by measuring the mRNA expression of transient receptor potential cation channel subfamily V member 1 (TRPV1) in musculus gastrocnemius.Methods: Seventy-two rats were randomly divided into five groups. Group A was the control group containing eight normal rats. Group B was the model group where 16 rats developed CMPS in musculus gastrocnemius but received no treatments. Groups C, D, and E containing 16 CMPS rats in each group were the trial groups receiving heat-conduction dry needling therapy. In detail, rats in Group C received dry needling treatment at the heating temperature of 44°C. Rats in Group D received intramuscular injection of capsazepine before receiving dry needling treatment with the heating temperature at 44°C. Rats in Group E received dry needling treatment with the heating temperature at 40°C. The mRNA expression of TRPV1, protein kinase C (PKC), and interleukin (IL)-6 in the needle insertion points of musculus gastrocnemius was measured at 24 hrs and 7 days after dry needling therapy.Results: Compared with untreated CMPS rats, the mRNA expression of TRPV1, PKC, and interleukin-6 (IL-6) was increased in rats receiving dry needling therapy with the heating temperature at 44°C for 24 hrs. However, the mRNA expression of TRPV1, PKC, and IL-6 in CMPS rats receiving injection of TRPV1 antagonist capsazepine into musculus gastrocnemius followed by temperature-needling at 44°C was analogous to that in untreated CMPS rats.Conclusion: Dry needling therapy with needles heated to 44°C could impact the activity of TRPV1/PKC/IL-6 pathway.Keywords: dry needling, myofascial pain syndrome, transient receptor potential, heat, capsazepine
