Abstract
It has been recently reported that Akt/mTOR signaling pathway is a crucial regulator of skeletal muscle hypertrophy. We have reported that the heat stress accelerates the recovery from skeletal muscle atrophy induced by hindlimb unweighting. Furthermore, we have showed heat stress-induced muscular hypertrophy in both the cultured skeletal muscle cells and the rat skeletal muscles. However, the mechanism responsible for the heat stress-induced muscular hypertrophy remains unclear. In this study, we investigated the role of the Akt signaling pathway in heat stress-induced muscle hypertrophy. Male Wistar strain rats (8-week-old) were mainly divided into two groups; control (Con) and heat stress (Heat). Heat groups were immersed into hot water (42°C) for 15 (H15), 30 (H30) and 60 min (H60). After 1 and 7 days, the plantaris muscles were dissected. Muscle weight-to-body weight ratio of H30 after 7 days was significantly higher than that of Con. The role of Akt signalling pathway in muscular hypertrophy induced by heat stress was examined. [Jpn J Physiol 54 Suppl:S119 (2004)]
