Wong N L, Halabe A, Wong E F, Sutton R A
Department of Medicine, University Hospital, University of British Columbia, Vancouver, Canada.
Metabolism. 1991 Feb;40(2):135-8. doi: 10.1016/0026-0495(91)90163-q.
Previous studies in our laboratory have shown that patients with idiopathic hypercalciuria (IH) have low basal atrial natriuretic factor (ANF) levels in the plasma. These depressed ANF levels are associated with a high plasma calcitriol levels. In this study, we have evaluated the effect of acute calcitriol administration on ANF release in the isolated atrium. There was a gradual reduction of ANF release as the dosage of calcitriol increased from 1 ng to 10 ng. Beyond 10 ng, additional suppression of ANF release by calcitriol was not observed. These results indicate that acute calcitriol administration causes a significant decrease in ANF release. To further determine whether this reduction in ANF release is due to changes in plasma calcium, additional studies were conducted to examine the effect of acute changes in perfusate calcium on ANF release by isolated atria. Acute elevation of perfusate calcium caused an increase in ANF release, whereas a reduction significantly decreased the secretory rate. These observations suggest that calcitriol affects ANF release by a mechanism not dependent on changes in plasma calcium.
我们实验室之前的研究表明，特发性高钙尿症（IH）患者血浆中的基础心房利钠因子（ANF）水平较低。这些降低的ANF水平与高血浆骨化三醇水平相关。在本研究中，我们评估了急性给予骨化三醇对离体心房中ANF释放的影响。随着骨化三醇剂量从1 ng增加到10 ng，ANF释放逐渐减少。超过10 ng后，未观察到骨化三醇对ANF释放的进一步抑制。这些结果表明，急性给予骨化三醇会导致ANF释放显著减少。为了进一步确定这种ANF释放的减少是否是由于血浆钙的变化，我们进行了额外的研究，以检查灌流液钙的急性变化对离体心房ANF释放的影响。灌流液钙的急性升高导致ANF释放增加，而降低则显著降低分泌率。这些观察结果表明，骨化三醇通过一种不依赖于血浆钙变化的机制影响ANF释放。
