Felipe C K Duarte1, Mark Hurtig2, Andrea Clark3, Jeremy Simpson4, John Z Srbely5. 1. Department of Human Health and Nutritional Science, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada. Electronic address: coutinhf@uoguelph.ca. 2. Department of Clinical Studies, Ontario Veterinary College, University of Guelph, 50 McGilvray Lane, Guelph, ON N1G 2W1, Canada. Electronic address: mhurtig@ovc.uoguelph.ca. 3. Department of Human Health and Nutritional Science, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada. Electronic address: alclark@uoguelph.ca. 4. Department of Human Health and Nutritional Science, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada. Electronic address: jeremys@uoguelph.ca. 5. Department of Human Health and Nutritional Science, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada. Electronic address: jsrbely@uoguelph.ca.
Abstract
OBJECTIVE: This study aimed to investigate the association between naturally occurring spinal osteoarthritis (OA) (L3-L5), the expression of substance P (SP) centrally (L4-L5) and the presence of neurogenic inflammation within the neurosegmentally linked quadriceps (L2-L5) in elderly rats versus young controls. DESIGN: Eight aged (27 ± 3.2 months) and six young (4 ± 0.0 months) male Wistar Kyoto rats were euthanized and submitted to micro-computerized tomography for determination of spine OA. SP expression (% area) at the dorsal horn of the spinal cord as well as the relative expression of SP and protease-activated receptor 2 (PAR2) to alpha-tubulin within quadriceps muscle were determined by immunohistochemistry and Western Blot. RESULTS: Spine osteoarthritis was confirmed in all aged rats but no young controls. Aged rats expressed significant increase of SP protein expression within the dorsal horn (MD = 0.086; 95% CI [0.026 to 0.145]; p = 0.0094) and quadriceps (MD = 1.209; 95% CI [0.239 to 2.179]; p = 0.0191) and PAR2 (MD = 0.797; 95% CI [0.160 to 1.435]; p = 0.0187) compared to young controls. CONCLUSION: These observations provide novel insight into the potential role of neurogenic inflammation in the pathophysiology of myofascial pain syndrome in the naturally occurring spinal OA in elderly population.
OBJECTIVE: This study aimed to investigate the association between naturally occurring spinal osteoarthritis (OA) (L3-L5), the expression of substance P (SP) centrally (L4-L5) and the presence of neurogenic inflammation within the neurosegmentally linked quadriceps (L2-L5) in elderly rats versus young controls. DESIGN: Eight aged (27 ± 3.2 months) and six young (4 ± 0.0 months) male Wistar Kyoto rats were euthanized and submitted to micro-computerized tomography for determination of spine OA. SP expression (% area) at the dorsal horn of the spinal cord as well as the relative expression of SP and protease-activated receptor 2 (PAR2) to alpha-tubulin within quadriceps muscle were determined by immunohistochemistry and Western Blot. RESULTS: Spine osteoarthritis was confirmed in all aged rats but no young controls. Aged rats expressed significant increase of SP protein expression within the dorsal horn (MD = 0.086; 95% CI [0.026 to 0.145]; p = 0.0094) and quadriceps (MD = 1.209; 95% CI [0.239 to 2.179]; p = 0.0191) and PAR2 (MD = 0.797; 95% CI [0.160 to 1.435]; p = 0.0187) compared to young controls. CONCLUSION: These observations provide novel insight into the potential role of neurogenic inflammation in the pathophysiology of myofascial pain syndrome in the naturally occurring spinal OA in elderly population.
Authors: Felipe C K Duarte; Daniel W D West; Lukas D Linde; Samah Hassan; Dinesh A Kumbhare Journal: Curr Rheumatol Rep Date: 2021-07-08 Impact factor: 4.592