Table 1. Influence of SIN-1 on Na+ and Cl− dependency of taurine uptake.
Uptake, fmol·mg protein−1 ·15 min−1 |
||
---|---|---|
Buffer | −SIN-1 (control) |
+SIN-1 |
NaCl (140 mM) | 2,036.6 ± 54.9 | 6,898.4 ± 94.2 |
NaCl (140 mM) + β-alanine (2.5 mM) | 94.6 ± 1.3 | 166.8 ± 5.9 |
NMDG-Cl (140 mM) | 27.9 ± 1.6 | 23.4 ± 1.7 |
Sodium gluconate (140 mM) | 49.3 ± 7.2 | 31.2 ± 3.4 |
Values are means ± SE. ARPE-19 cells were treated with or without 1 mM 3-morpholinosydnonimine (SIN-1) for 24 h, and uptake of [3H]taurine (80 nM) was measured. Uptake buffer consisted of 20 mM HEPES-Tris (pH 7.5) containing 140 mM NaCl, sodium gluconate, or N-methyl-d-glucamine (NMDG) chloride. Inhibition of taurine transport in the presence of β-alanine (in NaCl buffer) was also measured.