Fig. 1. (A) Effects of intravesicular polyvalent inorganic anions and mannitol on the time course of 25 µmol l^{–1 65}Zn²⁺ uptake by hepatopancreatic lysosomal membrane vesicles (LMV). Vesicles were loaded with 200 mmol l^–1 mannitol, 20 mmol l^–1 Hepes/Tris, pH 7.0, and 25 µmol l^–1 K₂SO₄, K₃PO₄ or mannitol, and were then incubated in a medium containing 200 mmol l^–1 mannitol, 25 µmol l^{–1 65}Zinc-sulfate, 0.5 mmol l^–1 NTA, 0.2 mmol l^–1 ATP and 20 mmol l^–1 Hepes/Tris, pH 7.0. (B) Effects of intravesicular monovalent inorganic anions (Cl^–1), polyvalent organic anions (oxalate^2–) and mannitol at pH 7.0 on the time course of 25 µmol l^{–1 65}Zn²⁺ uptake by LMV. Uptake conditions as in A except that in this instance vesicles were loaded with 25 µmol l^–1 oxalic acid, NaCl or mannitol. Experiments were conducted in triplicate; values are means ± 1 s.e.m. at each time point.