Bianchi J, Rose R C
Biochim Biophys Acta. 1985 Sep 25;819(1):75-82. doi: 10.1016/0005-2736(85)90197-x.
A membrane preparation enriched in the brush-border component of the plasma membrane was isolated from rat renal superficial cortex by a divalent cation precipitation procedure. Uptake of dehydro-L-ascorbic acid, the oxidized form of L-ascorbic acid, by the brush-border membrane vesicles was studied. The uptake mechanism was found to be sodium-independent and insensitive to the trans-membrane electrical potential difference. Uptake was saturable and subject to cis-inhibition. Concentrative uptake was demonstrated only under conditions of trans-stimulation by structural analogs. The results suggest a mechanism of facilitated diffusion for the uptake of dehydro-L-ascorbic acid in renal brush-border membranes.
通过二价阳离子沉淀法从大鼠肾浅表皮质分离出富含质膜刷状缘成分的膜制剂。研究了刷状缘膜囊泡对L-抗坏血酸的氧化形式脱氢-L-抗坏血酸的摄取。发现摄取机制不依赖于钠，并且对跨膜电势差不敏感。摄取是可饱和的，并受到顺式抑制。仅在结构类似物的反式刺激条件下才显示出浓缩摄取。结果提示了肾刷状缘膜中脱氢-L-抗坏血酸摄取的易化扩散机制。
