title: Beneficial effects of melatonin on stroke-induced muscle atrophy in focal cerebral ischemic rats.
abstract: MUSCLE ATROPHY IS THE RESULT OF TWO OPPOSING CONDITIONS THAT CAN BE FOUND IN PATHOLOGICAL OR DISEASED MUSCLES: an imbalance in protein synthesis and degradation mechanisms. Thus, we investigated whether exogenous melatonin could regulate muscle components in stroke-induced muscle atrophy in rats. Comparing muscle phenotypes, we found that long-term melatonin administration could influence muscle mass. Muscle atrophy-related genes, including muscle atrophy F-box (MAFbx) and muscle ring finger 1 (MuRF1) were significantly down-regulated in melatonin-administered rats in the gastrocnemius. However, only MAFbx at the mRNA level was attenuated in the soleus of melatonin-administered rats. Insulin-like growth factor-1 receptor (IGF-1R) was significantly over-expressed in melatonin-administered rats in both the gastrocnemius and soleus muscles. Comparing myosin heavy chain (MHC) components, in the gastrocnemius, expression of both slow- and fast-type isoforms were significantly enhanced in melatonin-administered rats. These results suggest that long-term exogenous melatonin-administration may have a prophylactic effect on muscle atrophy through the MuRF1/MAFbx signaling pathway, as well as a potential therapeutic effect on muscle atrophy through the IGF-1-mediated hypertrophic signaling pathway in a stroke animal model.
authors.affiliation: Department of Rehabilitation Science in Interdisciplinary PhD Program, Graduate School of Inje University, Gimhae, Korea.
authors.forename: Seunghoon
authors.initials: S
authors.lastname: Lee
authors.forename: Jinhee
authors.initials: J
authors.lastname: Shin
authors.forename: Yunkyung
authors.initials: Y
authors.lastname: Hong
authors.forename: Minkyung
authors.initials: M
authors.lastname: Lee
authors.forename: Koo
authors.initials: K
authors.lastname: Kim
authors.forename: Sang-Rae
authors.initials: SR
authors.lastname: Lee
authors.forename: Kyu-Tae
authors.initials: KT
authors.lastname: Chang
authors.forename: Yonggeun
authors.initials: Y
authors.lastname: Hong