Stokes J B
Am J Physiol. 1981 Jun;240(6):F471-80. doi: 10.1152/ajprenal.1981.240.6.F471.
The renal medulla is a rich source of prostaglandins. Two cell types, the collecting tubule epithelium and the interstitial cell, have the enzymatic machinery necessary to make prostaglandins. As a result of this localized production and the proximity to highly specialized medullary structures, the prostaglandins can exert potent effects on several aspects of medullary function. At least three physiologic effects have been clearly documented: reduction of vasopressin-dependent osmotic water permeability of the collecting tubule epithelium, enhancement of medullary blood flow, and inhibition of NaCl absorption from the thick ascending limb of Henle's loop. These three functions are the functions that primarily regulate axial solute content and water excretion. The effect of increasing medullary prostaglandin production is to reduce medullary solute content and increase water excretion. Each action in this regard. The medullary prostaglandins thus antagonize the ultimate action of vasopressin. In addition to the direct antagonistic effect on vasopressin-dependent osmotic water flow across the collecting tubule, prostaglandins and vasopressin may have antagonistic effects at other sites. These actions of medullary prostaglandins provide an integrated mechanism for the "fine tuning" of water excretion.
肾髓质是前列腺素的丰富来源。两种细胞类型，即集合管上皮细胞和间质细胞，具有合成前列腺素所需的酶机制。由于这种局部产生以及与高度特化的髓质结构接近，前列腺素可对髓质功能的多个方面产生强大影响。至少有三种生理效应已得到明确证实：降低集合管上皮细胞对血管加压素依赖性的渗透水通透性、增强髓质血流量以及抑制亨氏袢升支粗段对氯化钠的重吸收。这三种功能是主要调节轴向溶质含量和水排泄的功能。增加髓质前列腺素生成的作用是降低髓质溶质含量并增加水排泄。在这方面的每一个作用。因此，髓质前列腺素拮抗血管加压素的最终作用。除了对穿过集合管的血管加压素依赖性渗透水流有直接拮抗作用外，前列腺素和血管加压素可能在其他部位也有拮抗作用。髓质前列腺素的这些作用为水排泄的“微调”提供了一种综合机制。
