Effects of Inhibitors on ceftibuten and Gly-Sar uptake by rat intestinal BBM vesicles in the presence of an inward H+gradient
| Inhibitor | Uptake | |
|---|---|---|
| Ceftibuten | Gly-Sar | |
| pmol/mg protein/20 s | ||
| Control (pH 5.5out/7.5in) | 1437.0 ± 127.11-150 | 118.2 ± 18.11-150 |
| Without pH gradient (pH 7.5out/7.5in) | 343.7 ± 51.81-150 | 46.4 ± 8.81-150 |
| With FCCP (pH 5.5out/7.5in) | 680.1 ± 144.91-150 | N.D. |
| With pH gradient (pH 5.5out/7.5in) | 1390.1 ± 201.4 | 108.3 ± 2.5 |
| Voltage-clamped by valinomycin | ||
| l-Asp-l-Phe(20 mM) | 536.1 ± 86.71-150 | 140.1 ± 26.61-150 |
| l-Phe-l-Pro(20 mM) | 541.9 ± 60.91-150 | 45.5 ± 20.61-150 |
| l-Ala-l-Ala(20 mM) | 489.2 ± 89.31-150 | N.D. |
| l-Carnosine(20 mM) | 1428.3 ± 47.4 | 55.3 ± 18.61-150 |
| Gly-Sar (20 mM) | 1115.9 ± 104.51-150 | N.D. |
| Hippurylphenyl lactic acid (20 mM) | 337.4 ± 35.61-150 | 149.5 ± 18.2 |
| Cefixime (10 mM) | 1153.9 ± 37.41-150 | N.D. |
| Compound V (10 mM) | 506.7 ± 45.41-150 | N.D. |
| Ceftibuten (20 mM) | N.D. | 68.6 ± 13.11-150 |
Uptakes of 1.0 mM ceftibuten and 0.2 mM [14C]Gly-Sar into intestinal BBM vesicles in the presence of an inward H+gradient were measured for 20 s at 37°C with/without inhibitors, respectively. Each value represents mean ± S.E.M. Voltage-clamped BBM vesicles were prepared by adding valinomycin (6 μg/mg BBM protein) in the presence of equal concentrations of potassium at both the intravesicular and extravesicular space. The concentration of FCCP was 50 μM.
↵1-150 Significantly different compared with control (P < .05). N.D., not determined.