Figure 5
Effects of IBMX on 5-HT-induced changes in transepithelial potential (TEP) in Ba2+-containing PS. (A, B) Original recordings. The bar graphs (B, D) display and summarize the TEPs recorded at the time points (1–4) as indicated in A and C; means ± S.D. In both groups of experiments (A, C), an initial control stimulation with 30 nM 5-HT produces a biphasic TEP change. The TEP goes negative after superfusion of the preparation with Ba2+-containing PS. Addition of 1 nM and 30 nM 5-HT cause the TEP to go further negative. The TEP recorded in the presence of 1 nM 5-HT (A, B) but not 30 nM 5-HT (C, D) goes further negative by application of 500 μM IBMX in the presence of 5-HT.