Fig. 2. Effects of stimulation with 5-HT on (A) transepithelial potential (TEP),
(B) basolateral membrane potential (Vbl), (C), lumen pH
and(D) intracellular pH. The numbered phases of the response of
transepithelial potential to 5-HT are described in the text. Open arrows
indicate addition of 5-HT. Downward-pointing solid arrows indicate impalement
of the cell or lumen and upward-pointing solid arrows indicate the removal of
the electrode from the cell or lumen. (E,F) Values are means + s.e.m.;
N=5 tubules) for lumen and intracellular pH, respectively. The
asterisk indicates a significant difference (P<0.05, Student's
t-test) relative to unstimulated (i.e. phase 0) tubules.