Nerve growth factor increases sodium current in pancreatic β cells

Nerve growth factor (NGF) induces neurite-like process outgrowth in cultured adult pancreatic β cells. DbcAMP partially mimics this effect on cell morphology, and both compounds act synergistically to promote neurite-like process outgrowth. To determine if NGF- and dbcAMP-induced differentiation was accompanied by changes in β cell electrical activity, we studied the macroscopic Na current of adult rat β cells identified with the reverse hemolytic plaque assay and cultured for one week with these factors. After 5-7 days, β cells cultured in the presence of 2.5S NGF exhibited a 48% increase on the macroscopic Na current, which was due to an increase on Na current density. We did not observe changes on voltage dependence of current activation, nor on steady-state inactivation. Although dbcAMP also promotes changes on β cell morphology, it did not affect the Na current density.