Fig. 8. Effect of intravesicular pH on ³⁵SO₄^2– influx kinetics in hepatopancreatic LMV. In all cases extravesicular pH was held at pH 7.0. Vesicles were loaded with 200 mmol l^–1 mannitol, 20 mmol l^–1 Hepes/Tris at pH 7.0 (A), 8.0 (B) and 9.0 (C). Loaded vesicles were then incubated in media containing 2.5, 5, 10, 25 and 50 mmol l^–1 K₂³⁵SO₄, 20 mmol l^–1 Hepes/Tris, pH 7.0, and mannitol to maintain osmolarity. The experiment was repeated in triplicate; values are means ± 1 s.e.m. The sigmoidal curves were drawn through the data using Sigma Plot software (Jandel).