NAADP on the up in pancreatic beta cells-a sweet message?

Pancreatic beta cells secrete insulin in response to elevated plasma glucose levels in a Ca(2+)-dependent fashion. Released insulin may act on the beta cell itself to promote further insulin synthesis and release. Recent studies by Johnson and Misler,1 Masgrau et al.2 and Mitchell et al.3 provide strong evidence (1) for the existence of intracellular Ca(2+) stores sensitive to NAADP, a potent Ca(2+)-mobilizing messenger, and (2) that these Ca(2+) stores are involved in both glucose- and insulin-mediated signal transduction. NAADP may therefore play an important role in controlling secretion of insulin from pancreatic beta cells.