Na+ and H+ gradient-dependent transport of p-aminohippurate in membrane vesicles from dog kidney cortex.
Na+ and H+ gradient-dependent transport of p-aminohippurate in membrane vesicles from dog kidney cortex.
复制标题
狗肾皮质膜囊泡中对氨基马尿酸的 Na 和 H 梯度依赖性转运。
DOI:
10.1016/0006-2952(88)90258-4
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发表时间:
1988
影响因子:
5.8
通讯作者:
C. V. van Ginneken
中科院分区:
文献类型:
--
作者:
F. Russel;P. van der Linden;W. G. Vermeulen;M. Heijn;C. van Os;C. V. van Ginneken
The transport ofp-aminohippurate (PAH) was studied in basolateral (BLMV) and brush border membrane vesicles (BBMV) isolated from dog kidney cortex. Imposition of an inwardly directed 100 mN Na+gradient stimulated the uptake of 50 μM [3H]PAH into BLMV, whereas a pH gradient (pHout= 6.0, pHin= 7.4) only slightly enhanced uptake. The Na+gradient-dependent uptake of PAH was electroneutral, saturable and sensitive to inhibition by probenecid and several anionic drugs, with (apparent)Km= 0.79 ± 0.16 mM, Vnmax= 0.80 ± 0.05 nmol/mg protein,15 sec andKi, for probenecid = 0.08 ± 0.01 mM. Simultaneous imposition of the pH gradient (outward OH−gradient) and inward Na+gradient stimulated PAH uptake significantly over that with an Na+gradient alone. These results are consistent with an Na+gradient-stimulated PAH/OH−exchange mechanism in the basolateral membrane. In BBMV, PAH uptake could be stimulated by an outwardly directed OH−gradient as well as an inward Na+gradient. Both gradients could drive PAH transport via a mediated probenecidsensitive pathway. Na+gradient-stimulated uptake was electrogenic with a (apparent)Km= 4.93 ± 0.57 mM,Vmax= 6.71 ± 0.36 nmol/mg protein,15 sec andKi,prob= 0.13 ± 0.01 mM. The kinetic parameters for PAH/OH−exchange were virtually the same, (apparent)Km= 5.72 ± 0.49 mM,Vmax= 7.87 ± 0.33 nmol/mg protein, 15 sec andKi,prob= 0.16 ± 0.02 mM. When both the Na+and pH (outward OH−) gradient were simultaneously imposed an almost twofold stimulation in uptake was observed over that with either an Na+or pH gradient alone. These results suggested that both gradients stimulate PAH transport in BBMV via the same pathway. However, inhibition experiments with various organic anions showed that the specificities of Na+and pH gradient-stimulated PAH uptake do not entirely overlap. Thus, our results support a simple transport in BBMV, but it cannot be excluded that two separate pathways are involved.
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DOI:
10.1152/ajprenal.1983.244.1.f56
发表时间:
1983
期刊:
The American journal of physiology
影响因子:
--
作者:
Kahn,AM;Aronson,PS
通讯作者:
Aronson,PS
DOI:
10.1152/ajprenal.1984.246.1.f78
发表时间:
1984
期刊:
The American journal of physiology
影响因子:
--
作者:
Windus,DW;Cohn,DE;Klahr,S;Hammerman,MR
通讯作者:
Hammerman,MR
DOI:
10.1152/ajprenal.1982.243.3.f293
发表时间:
1982
期刊:
The American journal of physiology
影响因子:
--
作者:
Cohn,DE;Hruska,KA;Klahr,S;Hammerman,MR
通讯作者:
Hammerman,MR
DOI:
10.1016/0005-2736(87)90444-5
发表时间:
1987
期刊:
Biochimica et biophysica acta
影响因子:
--
作者:
Eveloff,J
通讯作者:
Eveloff,J
DOI:
10.1152/ajprenal.1984.246.5.f663
发表时间:
1984
期刊:
The American journal of physiology
影响因子:
--
作者:
Schwab,SJ;Klahr,S;Hammerman,MR
通讯作者:
Hammerman,MR