Fig. 4

Amperometry demonstrates that high glucose increases the quantal release of 5-HT from single EC cells. (a) A single amperometric spike indicating the different assessable parameters including the amplitude, area, rise-time and half-width. (b) An example amperometric trace before and during stimulation with 100 mM glucose (dashed line). Each spike represents 5-HT release from a single vesicle. (c) The frequency of vesicles releasing 5-HT is unchanged by high glucose but the spike (d) area and (e) amplitude are both increased. n = 8 cells per group. ** p < 0.01