| Autor: |
Sugiyamax, Yuichi, Kimura, Seiichi, Lin, Jiunn Huei, Izukura, Makoto, Awazu, Shoji, Hanano, Manabu |
| Zdroj: |
Journal of Pharmaceutical Sciences; August 1983, Vol. 72 Issue: 8 p871-876, 6p |
| Abstrakt: |
□ Uptake of the fluorescent probe, l-anilino-8-naphthalene-sulfonate (I) into isolated rat liver cells was studied using both fluorescence and filtration methods. The time course of the fluorescence enhancement of I after addition to the isolated liver cells was analyzed in terms of rapid, medium, and slow phases. The slow phase (half-time ~7min) was characteristic of viable cells. The fluorescence enhancement was proportional to the amount of I taken into the cells, as measured by the filtration method. The uptake of I followed Michaelis–Menten kinetics with an apparent Kmof 39μMand Vmaxof 1.4 nmole/106cells/min. The temperature coefficient (Q10) of the uptake of I was found to be ~1.9. No pH optimum was observed, and various metabolic inhibitors did not affect the uptake of I. Among the amino acid reagents used, only 2,4-dinitrofluorobenzene decreased the uptake of I (by −45%). The effects of various organic anions on the uptake of I were measured. The inhibition of the uptake of I by sulfobromophthalein could be analyzed in terms of competitive inhibition; the slight inhibition by sodium taurocholate could not. It is concluded that the uptake of I is a carrier-mediated facilitated process, and that the carrier is common to both I and sulfobromophthalein. |
| Databáze: |
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