The different membrane systems and proteins involved in the control of intracellular calcium movements in the skeletal muscle cell are described. These include the sarcoplasmic reticulum, that Ca(++)-ATPase sarcoplasmic reticular calcium pump, transverse tubules, calcium channels, and the ryanodine receptor protein. The significance of these systems is shown clearly in the myopathies, where the main errors involved do not concern the contractile system, but the command and control mechanisms.
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http://dx.doi.org/10.1016/s0750-7658(89)80003-6 | DOI Listing |
Front Physiol
January 2025
School of Kinesiology, Auburn University, Auburn, AL, United States.
Nitric oxide (NO) is a ubiquitous signaling molecule known to modulate various physiological processes, with specific implications in skeletal muscle and broader applications in exercise performance. This review focuses on the modulation of skeletal muscle function, mitochondrial adaptation and function, redox state by NO, and the effect of nitrate supplementation on exercise performance. In skeletal muscle function, NO is believed to increase the maximal shortening velocity and peak power output of muscle fibers.
View Article and Find Full Text PDFExp Brain Res
January 2025
Dept. of Neurosurgery, Upstate Medical University, 750 E. Adams St, Syracuse, NY, 13210, USA.
Transcranial magnetic stimulation (TMS) has been used for many years to study the pathophysiology of amyotrophic lateral sclerosis (ALS). Based on single- or dual-pulse TMS and EMG and/or single motor unit (MU) recordings, many groups have described a loss of central inhibition as an early marker of ALS dysfunction, reflecting a state of cortical 'hyperexcitability'. This conclusion is not without its detractors, however, leading us to reexamine this issue using 4-pulse TMS, shown previously to be more effective for testing central motor pathway functional integrity.
View Article and Find Full Text PDFJ Physiol Sci
January 2025
Department of Rehabilitation, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu-machi, Shimotsuga-gun, 321-0293, Tochigi, Japan. Electronic address:
The purpose of this study was the detection and characterization of synergistic muscle activity. Using T-map MRI, T values for 10 forearm muscles in 11 healthy adult volunteers were obtained in the resting state and after isotonic forearm supination and pronation exercises with the elbow extended. T was normalized by Z = (T-T)/SD, where T was T after exercise, while T and SD were the reference values of 34 ms and 3 ms, respectively.
View Article and Find Full Text PDFJ Physiol Sci
January 2025
Department of Physical Therapy, Faculty of Rehabilitation, Niigata University of Health and Welfare, 950-3198, Niigata, Japan; Institute for Human Movement and Medical Sciences (IHMMS), Niigata University of Health and Welfare, 950-3198, Niigata, Japan.
We reviewed fundamental studies on muscular pain, encompassing the characteristics of primary afferent fibers and neurons, spinal and thalamic projections, several muscular pain models, and possible neurochemical mechanisms of muscle pain. Most parts of this review were based on data obtained from animal experiments, and some researches on humans were also introduced. We focused on delayed-onset muscle soreness (DOMS) induced by lengthening contractions (LC), suitable for studying myofascial pain syndromes.
View Article and Find Full Text PDFClin Orthop Relat Res
January 2025
Department of Radiology, Chongqing Health Center for Women and Children/Women and Children's Hospital of Chongqing Medical University, Chongqing, PR China.
Background: Nonweightbearing preoperative assessments avoid quadriceps contraction that tends to affect patellar motion and appear to be inaccurate in quantifying anatomic factors, which can lead to incorrect corrections and postoperative complications.
Questions/purposes: (1) Does the relationship of patellar axial malalignment and other anatomic factors change during weightbearing? (2) What anatomic factor was most strongly correlated with recurrent patellar dislocation during weightbearing?
Methods: This prospective, comparative, observational study recruited participants at our institution between January 2023 and September 2023. During this time, all patients with recurrent patellar dislocations received both weightbearing and nonweightbearing CT scans; control patients who received unilateral CT scans because of injuries or benign tumors received both weightbearing and nonweightbearing CT scans.
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