NERVE GROWTH-FACTOR INCREASES SODIUM CURRENT IN PANCREATIC BETA-CELLS

Nerve growth factor (NGF) induces neurite-like process outgrowth in cu ltured adult pancreatic beta cells. DbcAMP partially mimics this effec t on cell morphology, and both compounds act synergistically to promot e neuritelike process outgrowth. To determine if NGF- and dbcAMP-induc ed differentiation was accompanied by changes in beta cell electrical activity, we studied the macroscopic Na current of adult rat beta cell s identified with the reverse hemolytic plaque assay and cultured for one week with these factors. After 5-7 days, beta cells cultured in th e 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 no t observe changes on voltage dependence of current activation, nor on steady-state inactivation. Although dbcAMP also promotes changes on be ta cell morphology, it did not affect the Na current density.