This study was undertaken to investigate thermal adaptations in muscle contractile properties in closely-related lizards with different preferred body temperatures (PBT). The species examined all belong to the Sphenomorphus group of Australian skinks (Scincidae: Lygosominae). Preferred body temperatures are conservative at the generic level as follows: Ctenotus, 35 degrees C; Sphenomorphus, 30 degrees C; Eremiascincus, 25 degrees C. Contractile properties of the fast glycolytic portion of the iliofibularis muscle were measured. Translational adaptations are evident in several isometric factors, including tetanic tension (Po), twitch tension (Pt), twitch time to peak tension (TPT), and twitch half-relaxation time (1/2 RT). Capacity adaptations are not evident in rates of tetanic tension development (dPo/dt) or in maximal velocities of isotonic shortening (Vmax). Rotational adaptations are not evident in any contractile properties. Thermal limits on upper response temperatures are about 5 degrees C warmer in Ctenotus than in the more cryophilic species, indicative of resistance adaptation in muscle performance. Despite these adaptive shifts, there is little indication that muscle functional capacities are optimized or equalized at PBT in these lizards.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/BF00692369 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Changes in H-reflex, V-wave and contractile properties of the plantar flexors following concurrent exercise sessions - the acute interference effect.
J Appl Physiol (1985)
December 2024
Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Portugal, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.
The interaction between muscle strength and endurance impacts athletic performance. Integrating both modalities into concurrent exercise (CE) is challenging due to the interference effect. This study explored the acute effects of resistance-only (R), endurance-only (E) and CE sessions on voluntary muscle strength, evoked neurophysiological parameters and contractile properties of the plantar flexors.
View Article and Find Full Text PDFConductive Microfibers Improve Stem Cell-Derived Cardiac Spheroid Maturation.
J Biomed Mater Res A
January 2025
Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, California, USA.
Conventional two-dimensional (2D) cardiomyocyte differentiation protocols create cells with limited maturity, which impairs their predictive capacity and has driven interest in three-dimensional (3D) engineered cardiac tissue models of varying maturity and scalability. Cardiac spheroids are attractive high-throughput models that have demonstrated improved functional and transcriptional maturity over conventional 2D differentiations. However, these 3D models still tend to have limited contractile and electrical maturity compared to highly engineered cardiac tissues; hence, we incorporated a library of conductive polymer microfibers in cardiac spheroids to determine if fiber properties could accelerate maturation.
View Article and Find Full Text PDFMolecular pathways involved in the control of contractile and metabolic properties of skeletal muscle fibers as potential therapeutic targets for Duchenne muscular dystrophy.
Front Physiol
December 2024
Institute of Biochemistry and Cell Biology, National Research Council (CNR), Monterotondo (RM), Italy.
Duchenne muscular dystrophy (DMD) is caused by mutations in the gene encoding dystrophin, a subsarcolemmal protein whose absence results in increased susceptibility of the muscle fiber membrane to contraction-induced injury. This results in increased calcium influx, oxidative stress, and mitochondrial dysfunction, leading to chronic inflammation, myofiber degeneration, and reduced muscle regenerative capacity. Fast glycolytic muscle fibers have been shown to be more vulnerable to mechanical stress than slow oxidative fibers in both DMD patients and DMD mouse models.
View Article and Find Full Text PDFEnhanced Vascular Smooth Muscle Cell and Extracellular Matrix Repair Using a Metal-Organic Framework-Based Co-Delivery System for Abdominal Aortic Aneurysm Therapy.
Adv Healthc Mater
December 2024
Department of Vascular Surgery, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325027, P. R. China.
The abdominal aortic aneurysm (AAA) is a severe and complex condition characterized by the pathological dilation of the abdominal aorta. Current therapeutic strategies are limited, with surgical repair being the most effective intervention due to the lack of medications that can slow aneurysmal expansion or prevent adverse events. In this study, an innovative nanoplatform, Mn-UiO-66-NH@HA, designed to repair vascular smooth muscle cells (VSMCs), and the extracellular matrix (ECM) is developed, thereby enhancing arterial wall integrity.
View Article and Find Full Text PDFC60 fullerene improves the contractile activity of the injured rat muscle gastrocnemius.
Nanotechnology
December 2024
Institute of Chemistry and Biotechnology, Technical University of Ilmenau, Weimarer Str. 25, Ilmenau, 98693, GERMANY.
The powerful antioxidant properties of C60 fullerenes have been widely used in biomedical nanotechnology. Owing to the negative effects of free radicals in oxidative stress processes, antioxidants are required to protect injured muscles. Here, the effect of water-soluble C60 fullerenes (daily oral dose 1 mg/kg) on the process of restoration of contractile activity of skeletal muscle of rats (muscle gastrocnemius) 15 days after the initiation of open trauma of different severity was studied for the first time.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!