Calcineurin-Mediated Slow-Type Fiber Expression and Growth in Reloading Condition.

The article investigates the functional role of calcineurin (CaN) as a regulator of muscle growth and/or muscle fiber type under conditions of recovery from inactivity. Female ICR mice were designated to eight weeks of hindlimb extension and subsequent reloading for four weeks. The animals were treated with pharmacological inhibitors for CaN by intraperitoneal administration during reloading. CaN signaling pathway has been found to have a role in muscle hypertrophy and the transcriptional regulation of slow muscle fiber genes.