Increased islet apoptosis in Pdx1^+/– mice
J. Clin. Invest. James D. Johnson, et al. 111:1147 doi:10.1172/JCI16537 [Go to this article.]

Figure 4
Single-cell exocytosis and voltage-gated Ca²⁺ currents are not altered in β cells from PDX1 transgenic mice. (a) A representative I/V curve made from consecutive (same-day) recordings of two Pdx1^+/– and two Pdx1^+/+ cells is shown. Analysis of voltage-gated Ca channels was performed on cells dispersed from six Pdx1^+/+ and six Pdx1^+/– mice. V_C, voltage. (b) Stimulated exocytosis is intact in Pdx1^+/– β cells. Results from both standard and TEA-treated conditions were pooled, and these results are summarized (n = 33 for Pdx1^+/+; n = 30 for Pdx1^+/–). C_m, membrane capacitance. Examples of changes in capacitance evoked by a train of 20 depolarizations (200 ms) from a holding potential of –70 mV to +10 mV in patch-clamped cells from Pdx1^+/+ (c, top panel) and Pdx1^+/– (d, top panel) islets. Recordings were made using a Cs⁺ pipette, with 30 mM TEA in the bath to simultaneously measure voltage-gated Ca²⁺ currents. Integrated Ca²⁺ charge entry is shown for each depolarization (bottom panels). Ca²⁺ current traces are shown for the first and 20th depolarizations (insets). Q(pC); charge entry; fF, femto Ferad.