Mefloquine, a useful tool to investigate hemichannel function in pancreatic beta cells?

Background and aims: It is generally assumed that potassium depolarization leads to the same depolarization-induced insulin secretion as the closure of KATP channels. We have found, however, that it leads to a strong further increase when KATP channels were blocked by tolbutamide. This effect involves increases of the cytosolic Ca2+ concentration. It is unclear however, whether the Ca2+ influx occurs via voltage-dependent Ca2+ channels or via connexin Cx36 hemichannels which are known to be sensitive to potassium depolarization. The involvement of hemichannels is typically tested using mefloquine. Methods: Membr…