Figure 1.

Proline uptake into rPAT2- and mPAT1-expressing X. laevis oocytes is dependent upon extracellular pH. Oocytes injected with water (50 nl) are used as a control for expression. Proline (100 μM) uptake was measured for 40 min in Na⁺-free conditions (22°C) over the extracellular pH range pH 5.0–7.4. Data are expressed as pmol oocyte⁻¹ (40 min)⁻¹ and are mean±s.e.m. (n=19–20).