Concurrent expression of erythroid and renal aquaporin CHIP and appearance of water channel activity in perinatal rats.
Concurrent expression of erythroid and renal aquaporin CHIP and appearance of water channel activity in perinatal rats.
复制标题
DOI：
10.1172/jci116798
复制
发表时间：
1993-10
期刊：
影响因子：
--
通讯作者：
Barbara L. Smith;Ruben Baumgarten;Søren Nielsen;D. M. Raben;M. Zeidel;P. Agre
中科院分区：
文献类型：
--
作者：
Barbara L. Smith;Ruben Baumgarten;Søren Nielsen;D. M. Raben;M. Zeidel;P. Agre
主要的表型变化发生在围产期的红细胞膜，但潜在的分子解释仍然不清楚。采用亲和纯化的抗CHIP IgG进行免疫印迹、流式细胞术和免疫荧光显微镜研究围产期大鼠红细胞和肾脏的主要水通道——水通道蛋白CHIP。CHIP未在产前红细胞中检测到，但在出生后第三天的循环红细胞中首次发现。大多数循环红细胞在出生后第7天CHIP阳性，到第14天这一比例上升到接近100%。红细胞CHIP的发生与渗透水通透性的获得直接相关，与阿伦尼乌斯活化能成反比。此时，只有细胞膜脂质的组成发生了微小的变化。围产期肾脏的免疫组织化学分析显示，出生时CHIP主要诱导肾近端小管和下降的细肢体，与肾脏浓度机制的发展相一致。因此，在产前循环中，水通道对于氧气输送或生存是不必要的，然而CHIP可能赋予红细胞在穿过肾髓质后迅速补水的能力，肾髓质在出生后变得高渗。
Major phenotypic changes occur in red cell membranes during the perinatal period, but the underlying molecular explanations remain poorly defined. Aquaporin CHIP, the major erythroid and renal water channel, was studied in perinatal rats using affinity-purified anti-CHIP IgG for immunoblotting, flow cytometry, and immunofluorescence microscopy. CHIP was not detected in prenatal red cells but was first identified in circulating red cells on the third postnatal day. Most circulating red cells were positive for CHIP by the seventh postnatal day, and this proportion rose to nearly 100% by the 14th day. The ontogeny of red cell CHIP correlated directly with acquisition of osmotic water permeability and inversely with Arrhenius activation energy. Only minor alterations in the composition of red cell membrane lipids occurred at this time. Immunohistochemical analysis of perinatal kidneys demonstrated a major induction of CHIP in renal proximal tubules and descending thin limbs at birth, coincident with the development of renal concentration mechanisms. Therefore, water channels are unnecessary for oxygen delivery or survival in the prenatal circulation, however CHIP may confer red cells with the ability to rehydrate rapidly after traversing the renal medulla, which becomes hypertonic after birth.