Na+ current properties in islet α- and β-cells reflect cell-specific Scn3a and Scn9a expression.

ABSTRACT: Mouse pancreatic β- and α-cells are equipped with voltage-gated Na(+) currents that inactivate over widely different membrane potentials (half-maximal inactivation (V0.5) at -100 mV and -50 mV in β- and α-cells, respectively). Single-cell PCR analyses show that both α- and β-cells have Nav1.3 (Scn3) and Nav1.7 (Scn9a) α subunits, but their relative proportions differ: β-cells principally express Nav1.7 and α-cells Nav1.3. In α-cells, genetically ablating Scn3a reduces the Na(+) current by 80%. In β-cells, knockout of Scn9a lowers the Na(+) current by >85%, unveiling a small Scn3a-dependent component. Glucagon and insulin secretion are inhibited in Scn3a(-/-) islets but unaffected in Scn9a-deficient islets. Thus, Nav1.3 is the functionally important Na(+) channel α subunit in both α- and β-

SUBMITTER: Zhang Q 

PROVIDER: S-EPMC4253470 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature