Calcium transport across segments of the rabbit distal nephron in vitro.
Calcium transport across segments of the rabbit distal nephron in vitro.
复制标题
体外钙转运穿过兔远端肾单位的各个部分。
DOI：
10.1152/ajprenal.1978.235.4.f367
复制
发表时间：
1978
期刊：
影响因子：
--
通讯作者：
L. Stoner
中科院分区：
文献类型：
--
作者：
G. Shareghi;L. Stoner
本文用离体灌流小管技术研究了远端肾单位各段钙转运的机制。在甲状旁腺激素（PTH）（3 × 10（-2）U/ml）存在下，远曲小管（DCT）和皮质集合管颗粒部分（CCT g）的钙吸收显著增强。Na+从DCT腔吸收，K+分泌到DCT腔。阿米洛利（5 × 10 ~（-5）M）或呋塞米（5 × 10 ~（-5）M）均能部分抑制Na ~+吸收，但对Ca ~（2+）吸收无影响。上述Na+的结果与DCT的异质性一致。净Na+吸收和K+分泌也发生在CCT g;这两个过程都被阿米洛利完全抑制。Ca 2+吸收发生在汉勒袢的粗升支; PTH没有增强，结果与被动运动一致。在有或无PTH或二丁酰环磷酸腺苷的情况下，在皮质集合小管的非颗粒（轻）段中未观察到净Ca 2+运动。
The mechanism of Ca2+ transport by various segments of the distal nephron was studied in vitro using the isolated perfused tubule technique. Calcium absorption in the distal convoluted tubule (DCT) and the granular portion of the cortical collecting duct (CCTg) was significantly enhanced in the presence of parathyroid hormone (PTH), 3 X 10(-2) U/ml. Na+ was absorbed from and K+ was secreted into the lumen of the DCT. The presence of amiloride (5 X 10(-5) M) or furosemide (5 X 10(-5) M) in the perfusate of DCT each caused a partial inhibition of Na+ but not Ca2+ absorption. The foregoing result with Na+ is consistent with the heterogeneous nature of DCT. Net Na+ absorption and K+ secretion also occurred in the CCTg; both processes were completely inhibited by amiloride. Ca2+ absorption occurred in the thick ascending limb of Henle's loop; it was not enhanced by PTH, and the results were consistent with passive movement. No net Ca2+ movement was observed in the nongranular (light) segment of the cortical collecting tubule in the presence or absence of PTH or dibutyryl cyclic adenosine monophosphate.