Figure 5.

The effects of GABA and related compounds on amino acid uptake in PAT1-expressing oocytes. (a) [³H]GABA (20 μM) uptake (pH 5.5, Na⁺-free) via hPAT1 was measured in the absence (control) or presence of unlabelled GABA, vigabatrin, TACA, guvacine or gabapentin (all 10 mM). Data are expressed as a percentage control ([³H]GABA uptake in the absence of unlabelled compounds) after subtraction of uptake in water-injected oocytes under identical experimental conditions. Data are mean±s.e.m. (n=18–20): ^**P<0.01 versus control. (b) [³H]GABA, [³H]β-alanine, [³H]glycine, [³H]proline (all 20 μM) uptake (pH 5.5, Na⁺-free) via mPAT1 was measured in the absence (open columns) or presence of GABA (filled columns) or vigabatrin (hatched columns) (both 10 mM). Data are expressed as mean±s.e.m. (n=10) following subtraction of uptake into water-injected oocytes under identical experimental conditions: ^**P<0.01 versus control.