RESUMEN
This study was undertaken in order to provide further insight into the role of leucine supplementation in the skeletal muscle regeneration process, focusing on myofiber size and strength recovery. Young (2-month-old) rats were subjected or not to leucine supplementation (1.35 g/kg per day) started 3 days prior to cryolesion. Then, soleus muscles were cryolesioned and continued receiving leucine supplementation until 1, 3 and 10 days later. Soleus muscles from leucine-supplemented animals displayed an increase in myofiber size and a reduction in collagen type III expression on post-cryolesion day 10. Leucine was also effective in reducing FOXO3a activation and ubiquitinated protein accumulation in muscles at post-cryolesion days 3 and 10. In addition, leucine supplementation minimized the cryolesion-induced decrease in tetanic strength and increase in fatigue in regenerating muscles at post-cryolesion day 10. These beneficial effects of leucine were not accompanied by activation of any elements of the phosphoinositide 3-kinase/Akt/mechanistic target of rapamycin signalling pathway in the regenerating muscles. Our results show that leucine improves myofiber size gain and strength recovery in regenerating soleus muscles through attenuation of protein ubiquitination. In addition, leucine might have therapeutic effects for muscle recovery following injury and in some muscle diseases.
Asunto(s)
Suplementos Dietéticos , Leucina/administración & dosificación , Músculo Esquelético/efectos de los fármacos , Distrofias Musculares/dietoterapia , Regeneración/efectos de los fármacos , Proteínas Quinasas Dependientes de 3-Fosfoinosítido/genética , Proteínas Quinasas Dependientes de 3-Fosfoinosítido/metabolismo , Administración Oral , Animales , Frío , Proteína Forkhead Box O3 , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Expresión Génica , Miembro Posterior , Masculino , Contracción Muscular/efectos de los fármacos , Músculo Esquelético/lesiones , Músculo Esquelético/metabolismo , Distrofias Musculares/genética , Distrofias Musculares/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Wistar , Transducción de Señal , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo , Ubiquitinación/efectos de los fármacosRESUMEN
Dystrophic mice (mdx) and their controls (C57/Bl10) were fed for 1 month with a diet with or without creatine (Cr) enrichment. Cr supplementation reduced mass (by 19%, P < 0.01) and mean fiber surface (by 25%, P < 0.05) of fast-twitch mdx muscles. In both strains, tetanic tension increased slightly (9.2%) without reaching statistical significance (P = 0.08), and relaxation time increased by 16% (P < 0.001). However, Cr had no protective effect on the other hallmarks of dystrophy such as susceptibility to eccentric contractions; large numbers of centrally nucleated fibers in tibialis anterior; and elevated total calcium content, which increased by 85% (P = 0.008) in gastrocnemius mdx muscles. In conclusion, Cr may be a positive intervention for improving function of dystrophic muscle.
Asunto(s)
Creatina/uso terapéutico , Suplementos Dietéticos , Músculo Esquelético/efectos de los fármacos , Distrofias Musculares/fisiopatología , Animales , Creatina/administración & dosificación , Técnicas In Vitro , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos mdx , Contracción Muscular/efectos de los fármacos , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Distrofias Musculares/dietoterapiaRESUMEN
The paper summarizes experience in treating 306 patients with progressive muscular dystrophy during different phases of the disease. The treatment was made with due consideration for a disturbed protein metabolism, a decreased permeability of the membrane in muscular filaments, a normalization of the metabolic product supply from the blood, improvement of the blood flow and cardio-vascular and respiratory insufficiency. The treatment was carried out in the form of a continuous use in in- and out-patient conditions of a session of anabolic hormones, vascular dilatative drugs, anticholinesterase preparations, amino acids, vitamins, drugs facilitating the cardio-vascular and respiratory activity. Besides, the patients were treated by oxygenobarotherapy, muscular electrostimulation by currents of sound frequencies, remedial gymnastics, massage, hypdrotherapy, etc. The authors propose typical treatment complexes. A follow-up study of patients who received a full course of therapy during three years demonstrated its effectiveness which was expressed by the absence of clinical signs of progressiveness.