Figure 2.

pH-dependent, Na⁺-independent, proline uptake into rPAT2- and mPAT1-expressing oocytes. Proline (100 μM) uptake was measured into (a) rPAT2- and (b) mPAT1-expressing oocytes (water-injected oocytes were used as a control) in the presence and absence of extracellular Na⁺ at pH 5.5, 6.5 and 7.4. Data are expressed as pmol oocyte⁻¹ (40 min)⁻¹ and are mean±s.e.m. (n=18–20). NS, P>0.05, uptake at each pH in Na⁺-containing vs Na⁺-free conditions.