
Fig. 2. Effect of bafilomycin A1 on acid secretion by intact turtle
bladders. Doseresponse inhibition curve. Turtle urinary bladders were
mounted in Ussing-type chambers and bathed in Na/Cl/HCO3 Ringer's
solution. The serosal solution contained 0.2 mmol l-1 ouabain.
Under these conditions the short-circuit current across the tissue
approximates the rate of net acid-base transport and is typically oriented
serosal-side negative (acid secretion; see Materials and methods). Baseline
acid secretion (100 %) was -12.0±4.3 µA (per area of chamber, 1.43
cm2) (N=4). Bafilomycin A1 in DMSO vehicle was
added in the luminal solution to the concentrations indicated and the
short-circuit current allowed to stabilize after each addition. The final
concentration of DMSO never exceeded 0.3 %.