Renal brush-border-membrane vesicles prepared from newborn rats by free-flow electrophoresis and their proline uptake.
Renal brush-border-membrane vesicles prepared from newborn rats by free-flow electrophoresis and their proline uptake.
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通过自由流动电泳从新生大鼠中制备肾刷状缘膜囊泡及其脯氨酸摄取。
DOI：
10.1042/bj2140209
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Segal,S
中科院分区：
文献类型：
--
作者：
Medow,MS;Roth,KS;Ginkinger,K;Segal,S
本文描述了一种分离新生大鼠肾刷边膜的方法，采用离心和自由流动电泳。通过测定各种细胞膜特异性酶活性来评价制剂的组成和纯度。自由流动电泳将新生大鼠肾膜悬浮液分解为两组富集碱性磷酸酶的刷状边界膜，分别称为“A”和“B”，其中A峰也显示（Na+ + K+）刺激的ATPase（基底外侧膜标记酶）的活性，而B峰的碱性磷酸酶活性富集11倍，（Na+ + K+）刺激的ATPase活性显著降低。A峰的膜显示碱性磷酸酶富集7倍，（Na+ + K+）刺激的atp酶活性与原始匀浆相似。用脯氨酸摄取来评估渗透依赖性显示脯氨酸与B囊泡的结合率为7%，与A囊泡的结合率为31%。这与单独离心制备的60%脯氨酸结合囊泡形成对比。与成年动物的囊泡不同，B囊泡对脯氨酸的摄取没有表现出Na+刺激的超调，但确实表现出Na+梯度增强的早期脯氨酸进入率。脯氨酸条目。
A method for the isolation of brush-border membranes from newborn-rat kidney, employing centrifugation and free-flow electrophoresis, is described. The composition and purity of the preparation was assessed by determination of enzyme activities specific for various cellular membranes. Free-flow electrophoresis resolves the newborn-rat renal membrane suspension into two populations of alkaline phosphatase-enriched brush-border membranes, designated ‘A’ and ‘B’, with the A peak also showing activity of (Na+ + K+)-stimulated ATPase, the basolateral membrane marker enzyme, whereas those of the B peak were enriched 11-fold in alkaline phosphatase and substantially decreased in (Na+ + K+)-stimulated ATPase activity. Membranes in the A peak showed a 7-fold enrichment of alkaline phosphatase, and (Na+ + K+)-stimulated ATPase activity similar to that of the original homogenate. Proline uptake employed to assess osmotic dependency revealed 7% binding of proline to the B vesicles and 31% to the A vesicles. This contrasts with 60% proline binding to vesicles prepared by centrifugation alone. Unlike vesicles from adult animals, proline uptake by B vesicles did not show an Na+-stimulated overshoot, but did exhibit an Na+-gradient enhanced rate of early proline entry. proline entry.