The perspective of long-duration flights for future exploration, imply more research in the field of human adaptation. Previous studies in rat muscles hindlimb suspension (HLS), indicated muscle atrophy and a change of fibre composition from slow-to-fast twitch types. However, the contractile responses to long-term unloading is still unclear. Fifteen adult Wistar rats were studied in 45 and 70 days of muscle unweighting and soleus (SOL) muscle as well as extensor digitorum longus (EDL) were prepared for electrophysiological recordings (single, twitch, tetanic contraction and fatigue) and histochemical stainings. The loss of muscle mass observed was greater in the soleus muscle. The analysis of electrophysiological properties of both EDL and SOL showed significant main effects of group, of number of unweighting days and fatigue properties. Single contraction for soleus muscle remained unchanged but there was statistically significant difference for tetanic contraction and fatigue. Fatigue index showed a decrease for the control rats, but increase for the HLS rats. According to the histochemical findings there was a shift from oxidative to glycolytic metabolism during HLS. The data suggested that muscles atrophied, but they presented an adaptation pattern, while their endurance in fatigue was decreased.
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http://dx.doi.org/10.1016/j.actaastro.2003.10.001 | DOI Listing |
Nutrients
December 2024
Cooperative Major of Advanced Health Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei 184-8588, Tokyo, Japan.
Background: Lutein, a carotenoid, exhibits various biological activities such as maintaining the health of the eye, skin, heart, and bone. Recently, we found that lutein has dual roles in suppressing bone resorption and promoting bone formation. In this study, we examined the effects of lutein in a disuse-induced osteoporosis model using hindlimb-unloaded (HLU) mice.
View Article and Find Full Text PDFShock
December 2024
Department of Surgery, University of Texas Medical Branch, Galveston, TX, USA.
Background: Loss of muscle mass and strength in patients who have experienced severe burns is dramatic and associated with subsequent functional impairment. Past work has shown that exercise and oxandrolone, an anabolic steroid, individually improve muscle function and muscle mass in severely burned patients. This study aims to evaluate the effect of oxandrolone treatment combined with resistance exercise on muscle atrophy and investigate the protein synthesis and mitochondrial biogenesis pathways in a hindlimb suspension model.
View Article and Find Full Text PDFIn Vivo
December 2024
Laboratory of Physiology, School of Health Sciences, Toyohashi SOZO University, Toyohashi, Japan;
Background/aim: Lactate is a physiologically active substance secreted by skeletal muscle that has been suggested to stimulate muscle mass gain. However, the molecular mechanism for lactate-associated muscle hypertrophy remains unclear. The purpose of the present study was to investigate whether oral administration of lactate increases muscle mass under different loading conditions.
View Article and Find Full Text PDFInt J Dev Neurosci
February 2025
Department of Clinical Sciences, Faculty of Veterinary Medicine, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Quercetin is a natural flavonoid and one of the most powerful antioxidants. Due to its wide range of biological properties, it may improve cognitive and physical performance by affecting nervous tissue. The current study is aimed at determining the effect of prenatal exposure to quercetin against methimazole (MMI)-induced hypothyroidism on reflexive motor behavior in mouse offspring.
View Article and Find Full Text PDFToxicol Appl Pharmacol
December 2024
Department of Applied Chemistry and Life Sciences, Graduate School of Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580, Japan; Center for Diversity and Inclusion, Toyohashi University of Technology, Toyohashi, Aichi, 441-8580, Japan. Electronic address:
Concerns have been raised regarding acetamiprid (ACE), a neonicotinoid insecticide, due to its potential neurodevelopmental toxicity. ACE, which is structurally similar to nicotine, acts as an agonist of nicotinic acetylcholine receptors (nAChRs) and resists degradation by acetylcholinesterase. Furthermore, ACE has been reported to disrupt neuronal transmission and induce developmental neurotoxicity and ataxia in animal models.
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