1
|
Makar D, Nazemi A, Gong SG, Bhardwaj N, De Guzman R, Sessle BJ, Cioffi I. Development of a model to investigate the effects of prolonged ischaemia on the muscles of mastication of male Sprague Dawley rats. Arch Oral Biol 2023; 146:105602. [PMID: 36543038 DOI: 10.1016/j.archoralbio.2022.105602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 12/02/2022] [Accepted: 12/04/2022] [Indexed: 12/12/2022]
Abstract
OBJECTIVE The aims of this study were to develop a novel rodent model of masticatory muscle ischaemia via unilateral ligation of the external carotid artery (ECA), and to undertake a preliminary investigation to characterize its downstream effects on mechanosensitivity and cellular features of the masseter and temporalis muscles. DESIGN The right ECA of 18 male Sprague-Dawley rats was ligated under general anaesthesia. Mechanical detection thresholds (MDTs) at the masseter and temporalis bilaterally were measured immediately before ECA ligation and after euthanasia at 10-, 20-, and 35-days (n = 6 rats/timepoint). Tissue samples from both muscles and sides were harvested for histological analyses and for assessing changes in the expression of markers of hypoxia and muscle degeneration (Hif-1α, VegfA, and Fbxo32) via real time PCR. Data were analyzed using mixed effect models and non-parametric tests. Statistical significance was set at p < 0.05. RESULTS MDTs were higher in the right than left hemiface (p = 0.009) after 20 days. Histological changes indicative of muscle degeneration and fibrosis were observed in the right muscles. Hif-1α, VegfA, and Fbxo32 were more highly expressed in the masseter than temporalis muscles (all p < 0.05). Hif-1α and, VegfA did not change significantly with time in all muscles (all p > 0.05). Fbxo32 expression gradually increased in the right masseter (p = 0.024) and left temporalis (p = 0.05). CONCLUSIONS ECA ligation in rats induced hyposensitivity in the homolateral hemiface after 20 days accompanied by tissue degenerative changes. Our findings support the use of this model to study pathophysiologic mechanisms of masticatory muscle ischaemia in larger investigations.
Collapse
Affiliation(s)
- D Makar
- University of Toronto, Faculty of Dentistry, Centre for Multimodal Sensorimotor and Pain Research, Toronto, ON, Canada; University of Toronto, Faculty of Dentistry, Graduate Orthodontics, Toronto, ON, Canada
| | - A Nazemi
- University of Toronto, Faculty of Dentistry, Centre for Multimodal Sensorimotor and Pain Research, Toronto, ON, Canada
| | - S G Gong
- University of Toronto, Faculty of Dentistry, Graduate Orthodontics, Toronto, ON, Canada
| | - N Bhardwaj
- University of Toronto, Faculty of Medicine, Department of Comparative Medicine, Toronto, ON, Canada; Peter Gilgan Centre for Research and Learning, Sickkids Hospital, Toronto, ON, Canada
| | - R De Guzman
- University of Toronto, Faculty of Medicine, Department of Comparative Medicine, Toronto, ON, Canada
| | - B J Sessle
- University of Toronto, Faculty of Dentistry, Toronto, ON, Canada; University of Toronto, Faculty of Medicine, Department of Physiology, Toronto, ON, Canada
| | - I Cioffi
- University of Toronto, Faculty of Dentistry, Centre for Multimodal Sensorimotor and Pain Research, Toronto, ON, Canada; Mount Sinai Hospital, Department of Dentistry, Toronto, ON, Canada; University of Toronto, Faculty of Dentistry, Graduate Orthodontics, Toronto, ON, Canada.
| |
Collapse
|
2
|
Avrillon S, Hug F, Guilhem G. Bilateral differences in hamstring coordination in previously injured elite athletes. J Appl Physiol (1985) 2020; 128:688-697. [PMID: 32027546 DOI: 10.1152/japplphysiol.00411.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Hamstring strain injuries (HSIs) involve tissue disruption and pain, which can trigger long-term adaptations of muscle coordination. However, little is known about the effect of previous HSIs on muscle coordination and in particular, after the completion of rehabilitation and in the absence of symptoms. This study aimed to determine if elite athletes with a prior unilateral HSI have bilateral differences in coordination between the hamstring muscle heads after returning to sport. Seventeen athletes with a unilateral history of biceps femoris (BF) injury participated in the experiment. Surface electromyography was recorded from three hamstring muscles [BF, semimembranosus (SM), and semitendinosus] during submaximal isometric torque-matched tasks at 20% and 50% of maximal voluntary contraction. The product of normalized electromyographic amplitude with functional physiological cross-sectional area (PCSA) and moment arm was considered as an index of individual muscle torque. The contribution of the injured muscle to total knee flexion torque was lower in the injured than the uninjured limb (-5.6 ± 10.2%, P = 0.038). This reduced contribution of BF was compensated by a higher contribution of the SM muscle in the injured limb (+5.6 ± 7.5%, P = 0.007). These changes resulted from a lower contribution of PCSA from the injured muscle (BF) and a larger contribution of activation from an uninjured synergist muscle (SM). In conclusion, bilateral differences in coordination were observed in previously injured athletes despite the completion of rehabilitation. Whether these bilateral differences in hamstring coordination could constitute an intrinsic risk factor that contributes to the high rate of hamstring injury recurrence remains to be investigated.NEW & NOTEWORTHY We used an experimental approach, combining the assessment of muscle activation, physiological cross-sectional area, and moment arm to estimate force-sharing strategies among hamstring muscles during isometric knee flexions. We tested athletes with a history of hamstring injury. We observed a lower contribution of the injured biceps femoris to the total knee flexor torque in the injured limb than in the contralateral limb. This decreased contribution was mainly due to selective atrophy of the injured biceps femoris muscle and was compensated by an increased activation of the semimembranosus muscle.
Collapse
Affiliation(s)
- Simon Avrillon
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport, Paris, France.,Laboratory Movement, Interactions, Performance (EA 4334), Nantes University, Nantes, France.,Legs & Walking Lab, Shirley Ryan AbilityLab, Chicago, Illinois.,Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - François Hug
- Laboratory Movement, Interactions, Performance (EA 4334), Nantes University, Nantes, France.,Institut Universitaire de France, Paris, France.,School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia
| | - Gaël Guilhem
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport, Paris, France
| |
Collapse
|
3
|
Do individual differences in the distribution of activation between synergist muscles reflect individual strategies? Exp Brain Res 2018; 237:625-635. [DOI: 10.1007/s00221-018-5445-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 11/24/2018] [Indexed: 12/20/2022]
|
4
|
BRØCHNER NIELSEN NIELSPETER, HUG FRANÇOIS, GUÉVEL ARNAUD, COLLOUD FLOREN, LARDY JULIEN, DOREL SYLVAIN. Changes in Motor Coordination Induced by Local Fatigue during a Sprint Cycling Task. Med Sci Sports Exerc 2018; 50:1394-1404. [DOI: 10.1249/mss.0000000000001572] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|