Oxytocin stimulates glucose uptake in skeletal muscle cells through the calcium-CaMKK-AMPK pathway.

Oxytocin is a mammalian hormone that is released mainly after distension of the uterine cervix. In this study, we report that oxytocin stimulates intracellular release of calcium, and also activates AMPK (AMP-activated protein kinase) in C2C12 myoblast cells in a time/dose-dependent manner. Oxytocin receptor mRNA was detected in C2C12 cells. In addition, oxytocin stimulated glucose uptake and, moreover, inhibition of either CaMKK (Ca(2+)/calmodulin-dependent protein kinase kinase) or AMPK blocked oxytocin-mediated AMPK activation and glucose uptake. Taken together, our findings suggest that oxytocin may serve a peripheral metabolic function in skeletal muscle cells through the calcium-CaMKK-AMPK pathway.