Figure 1

Effects of purinergic agonists on short circuit current of SCCD epithelium. Representative recordings of apical (AP) and basolateral (BL) addition of purinergic agonists to SCCD epithelia. The continuous line is the open-circuit transepithelial voltage (V_T) and the pulses are the voltage response to current pulses. A) ATP was added to the apical or basolateral chamber at the times indicated by the bars at the top of the figure. A single pulse is shown with an expanded time scale in the insert for clarity and shows no time-dependent response. Vertical arrows indicate where readings were taken for the initial (I) value, change after apical (ΔA) agonist, peak basolateral (B_p) and change after basolateral (ΔB) agonist for tabulation in Table 2. B) UTP was added to the apical or basolateral chamber at the times indicated by the bars at the top of the figure; example of recording with transient increase in V_T after basolateral addition of UTP. C) Similar to recording in B, but an example of a recording without transient increase in V_T after basolateral addition of UTP.