Referenced in: none

Automatically associated channels: SK3 , TRP , TRPV , TRPV1

Title: Capsaicin mimics mechanical load-induced intracellular signaling events: involvement of TRPV1-mediated calcium signaling in induction of skeletal muscle hypertrophy.

Authors: Naoki Ito, Urs T Ruegg, Akira Kudo, Yuko Miyagoe-Suzuki, Shin'ichi Takeda

Journal, date & volume: Channels (Austin), 2013 May-Jun , 7, 221-4

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/23584166

Abstract
Mechanical load-induced intracellular signaling events are important for subsequent skeletal muscle hypertrophy. We previously showed that load-induced activation of the cation channel TRPV1 caused an increase in intracellular calcium concentrations ([Ca ( 2+) ]i) and that this activated mammalian target of rapamycin (mTOR) and promoted muscle hypertrophy. However, the link between mechanical load-induced intracellular signaling events, and the TRPV1-mediated increases in [Ca ( 2+) ]i are not fully understood. Here we show that administration of the TRPV1 agonist, capsaicin, induces phosphorylation of mTOR, p70S6K, S6, Erk1/2 and p38 MAPK, but not Akt, AMPK or GSK3β. Furthermore, the TRPV1-induced phosphorylation patterns resembled those induced by mechanical load. Our results continue to highlight the importance of TRPV1-mediated calcium signaling in load-induced intracellular signaling pathways.