McGiff J C, Laniado-Schwartzman M
Department of Pharmacology, New York Medical College, Valhalla.
Clin Physiol Biochem. 1988;6(3-4):179-87.
The medullary portion of the thick ascending limb of the loop of Henle (TALH) has one of the highest concentrations of Na+-K+-ATPase found in mammalian tissues, reflecting the importance of this nephron segment in the regulation of extracellular fluid volume, as active sodium transport is driven by Na+-K+-ATPase. We have isolated cells derived primarily from the TALH of the outer medulla of rabbit kidney and have identified a cytochrome P450-dependent monooxygenase system which metabolizes arachidonic acid to two biologically active oxygenated peaks, each containing two or more products. One of the peaks potently inhibits cardiac Na+-K+-ATPase and the other relaxes blood vessels. We report that formation of these oxygenated arachidonate metabolites is stimulated by arginine vasopressin and salmon calcitonin. In TALH cells obtained from rabbits made hypertensive by aortic constriction there was a selective increase in P1 and P2 formation compared to other renomedullary cells.
亨氏袢厚壁升支髓质部（TALH）具有哺乳动物组织中发现的最高浓度的钠钾ATP酶之一，这反映了该肾单位节段在调节细胞外液量中的重要性，因为活性钠转运由钠钾ATP酶驱动。我们已分离出主要源自兔肾外髓质TALH的细胞，并鉴定出一种细胞色素P450依赖性单加氧酶系统，该系统将花生四烯酸代谢为两个具有生物活性的氧化峰，每个峰包含两种或更多种产物。其中一个峰强烈抑制心脏钠钾ATP酶，另一个峰使血管舒张。我们报告说，精氨酸加压素和鲑鱼降钙素可刺激这些氧化花生四烯酸代谢产物的形成。在由主动脉缩窄导致高血压的兔子的TALH细胞中，与其他肾髓质细胞相比，P1和P2的形成有选择性增加。
