Effect of hypothermia was studied on the twitch and tetanic contractions of the chronically denervated rat diaphragm muscles under isotonic conditions. The muscles were denervated for 15-20 days and the temperature was lowered from 35 degrees C to 15 degrees C. The results showed that hypothermia and chronic denervation had very little effect on the isotonic contraction parameters since these were found to be unaltered at all temperatures except at 15 degrees C. It is suggested that denervation has no significant effect on the contractile component of our experimental muscles.
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January 2025
Department of Neurobiology, Poznan University of Physical Education, Poznan, Poland.
Previously, boost and sag effects seen in unfused tetanic contractions have been studied exclusively at constant stimulation frequency. However, intervals between successive discharges of motoneurons vary during voluntary movements. We therefore aimed to test whether the extra-efficient force production at the onset of contraction (boost) occurs during stimulation with variable intervals, and to what extent it depends on the level of interpulse interval (IPI) variability and history of stimulation.
View Article and Find Full Text PDFZhonghua Yi Xue Za Zhi
January 2025
Department of Biomedical Statistics, Peking University First Hospital, Beijing100034, China.
To evaluate the efficacy of domestic and imported sugammadex for reversal of rocuronium-induced deep neuromuscular block (NMB) in adult patients. The clinical data of adult patients who scheduled for elective surgery with general anesthesia that required muscle relaxants in Peking University First Hospital from June 2023 to June 2024 were prospectively included. The patients were devided into domestic group and imported group according to random number table method.
View Article and Find Full Text PDFSkelet Muscle
January 2025
Department of Anesthesia and Critical Care, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Background: Duchenne muscular dystrophy (DMD) is a prevalent, fatal degenerative muscle disease with no effective treatments. Mdx mouse model of DMD exhibits impaired muscle performance, oxidative stress, and dysfunctional autophagy. Although antioxidant treatments may improve the mdx phenotype, the precise molecular mechanisms remain unclear.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
December 2024
Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, Riverside, California, USA.
The optimum length for force generation () increases as activation is reduced, challenging classic theories of muscle contraction. Although the activation dependence of is seemingly consistent with length-dependent Ca sensitivity, this mechanism can't explain the apparent force dependence of , or the effect of series compliance on activation-related shifts in . We have tested a theory proposing that the activation dependence of relates to force depression resulting from shortening against series elasticity.
View Article and Find Full Text PDFArch Biochem Biophys
February 2025
Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, Shaanxi, China. Electronic address:
Mechanical unloading can lead to homeostasis imbalance and severe muscle disease, in which muscle atrophy was one of the disused diseases. However, there were limited therapeutic targets for such diseases. In this study, miR-495 was found dramatically reduced in atrophic skeletal muscle induced by mechanical unloading models both in vitro and in vivo, including the random positioning model (RPM), tail-suspension (TS) model, and aged mice model.
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