Fig. 4. Effect of preloaded Cl^– on the time course of ³⁵SO₄^2– and ¹⁴C-oxalate^2– uptake by hepatopancreatic lysosomal membrane vesicles. (A) Vesicles were loaded with 200 mmol l^–1 mannitol, 20 mmol l^–1 Hepes/Tris, pH 7.0, with or without 0.5 mmol l^–1 KCl, and were incubated in media containing 200 mmol l^–1 mannitol, 20 mmol l^–1 Hepes/Tris, pH 7.0, with or without 0.5 mmol l^–1 potassium gluconate and 5 mmol l^–1 K₂³⁵SO₄. (B) Vesicles were loaded with 200 mmol l^–1 mannitol, 20 mmol l^–1 Hepes/Tris, pH 7.0, with or without 0.5 mmol l^–1 KCl, and were incubated in media containing 200 mmol l^–1 mannitol, 20 mmol l^–1 Hepes/Tris, pH 7.0, with or without 0.5 mmol l^–1 potassium gluconate, and 5 mmol l^{–1 14}C-oxalate^2–. Experiments were in triplicate; values are means ± 1 s.e.m. at each time point.