Overbeck H W, Wallick E T, Shikuma R, Magargal W W
Department of Medicine, University of Alabama, Birmingham 35294.
Hypertension. 1988 Jul;12(1):32-8. doi: 10.1161/01.hyp.12.1.32.
We investigated the effects of plasma from dogs with perinephritic hypertension on the Na+-K+ pump of cultured dog vascular smooth muscle cells. We also measured [3H]ouabain binding by myocardium and vascular tissue. Fresh, unprocessed plasma from healthy dogs during the first 6 weeks of benign one-kidney, one wrapped hypertension and from paired normotensive control dogs was layered over confluent primary cultured puppy aortic smooth muscle cells that had been sodium-loaded with monensin. In 26 paired assays of plasma from four pairs of dogs, cells incubated in the presence of plasma from hypertensive dogs had significantly reduced total (p less than 0.01) and ouabain-sensitive (p less than 0.001) 86Rb+ uptakes, but their intracellular sodium content did not differ from cells incubated in paired normotensive plasma. We no longer detected these uptake differences when passaged cells or cells cocultured with bovine endothelial cells were used for assay or when plasma was treated with protease inhibitors or boiled. However, boiled plasma increased the sodium content of the assay cells, suggesting an ionophorelike effect. Levels of pump inhibitory activity in plasma appeared to remain constant during Weeks 1 to 6 of hypertension. We found no evidence for altered numbers of pump sites in cardiovascular tissues from these hypertensive dogs. These findings support the hypothesis that plasma factors inhibit the membrane Na+-K+ pump in vascular smooth muscle cells in this form of hypertension. These plasma inhibitory factors apparently do not induce pump molecules.
我们研究了患有肾周性高血压的犬血浆对培养的犬血管平滑肌细胞钠钾泵的影响。我们还测量了心肌和血管组织中[3H]哇巴因的结合情况。将来自良性单肾单包绕高血压犬前6周的新鲜、未处理血浆以及配对的正常血压对照犬的血浆，铺在已用莫能菌素进行钠负载的汇合原代培养幼犬主动脉平滑肌细胞上。在对四对犬的26对血浆检测中，在高血压犬血浆存在下孵育的细胞，其总的（p<0.01）和哇巴因敏感的（p<0.001）86Rb+摄取量显著降低，但其细胞内钠含量与在配对正常血压血浆中孵育的细胞并无差异。当使用传代细胞或与牛内皮细胞共培养的细胞进行检测时，或者当血浆用蛋白酶抑制剂处理或煮沸时，我们不再检测到这些摄取差异。然而，煮沸的血浆增加了检测细胞的钠含量，提示有类似离子载体的作用。在高血压的第1至6周期间，血浆中泵抑制活性水平似乎保持恒定。我们没有发现这些高血压犬心血管组织中泵位点数量改变的证据。这些发现支持了这样一种假说，即血浆因子在这种高血压形式中抑制血管平滑肌细胞中的膜钠钾泵。这些血浆抑制因子显然不会诱导泵分子。
