کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4065746 1266272 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Physiological, histological and biochemical properties of rat skeletal muscles in response to hindlimb suspension
موضوعات مرتبط
علوم پزشکی و سلامت پزشکی و دندانپزشکی ارتوپدی، پزشکی ورزشی و توانبخشی
پیش نمایش صفحه اول مقاله
Physiological, histological and biochemical properties of rat skeletal muscles in response to hindlimb suspension
چکیده انگلیسی

In previous study, we found that the reduced exercise-induced production of reactive oxygen species (ROS) reported in slow-oxidative muscle of hypoxemic rats and also in chronic hypoxemic patients did not simply result from deconditioning. In control rats and after a 3-week period of hindlimb suspension (HS), the slow-oxidative (Soleus, SOL) and fast-glycolytic skeletal muscles (Extensor digitorum longus, EDL) were sampled. We determined the response to direct muscle stimulation (twitch stimulation (TS), Maximal force (Fmax)), twitch amplitude and maximal relaxation rate, tetanic frequency, endurance to fatigue after muscle stimulation (MS), the different fibre types based on their myofibrillar adenosinetriphosphatase (ATPase) activity, and the intra-muscular redox status (Thiobarbituric Acid Reactive Sustances: TBARS, reduced glutathione: GSH, reduced ascorbic acid: RAA). After the 3-w HS period: (1) the contractile properties were modified in SOL only (reduced Fmax and twitch amplitude, increased tetanic frequency); (2) the fibre typology was modified in both muscles (in SOL: increased proportion of IIa and IIc fibres, in EDL: increased proportion of IId/x fibres but decreased proportion of IIb fibres); and (3) only in SOL, the TBARS level increased and the GSH and RAA concentrations decreased at rest and after fatiguing MS. Thus, HS accentuates the exercise-induced ROS production in slow-oxidative muscle in a direction opposite to that measured in chronic hypoxemic rats. This strongly suggests that hypoxemia reduces the ROS production independently from any muscle disuse.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Electromyography and Kinesiology - Volume 18, Issue 2, April 2008, Pages 276–283
نویسندگان
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