Doris P A
Department of Cell Biology and Anatomy, Texas Tech University Health Sciences Center, School of Medicine, Lubbock 79430.
Peptides. 1988 Mar-Apr;9(2):243-8. doi: 10.1016/0196-9781(88)90256-2.
Interactions between sodium and calcium metabolism and the renin angiotensin system (RAS) have been studied. In rats drinking highly palatable 0.5% sodium chloride solution for a 6 month period, plasma angiotensin II (p[AII]) levels after 6 months did not differ from control animals drinking water. However, plasma ionized calcium (p[iCa]) levels were significantly reduced compared to controls. In a third group of animals which drank saline, but consumed a calcium supplemented chow (2% calcium by weight vs. 1%), p[AII] was significantly elevated above both other groups. Further experiments were performed to study short term (4 weeks) changes in calcium intake and p[AII] levels. Diets contained high (4%), normal (1%) and low (0.05%) calcium content. All animals drank water. Plasma total calcium (p[tCa]) and p[iCa] concentration were elevated in the 4% calcium group compared with 1% calcium. In the 0.05% calcium group, p[iCa] was significantly reduced compared with the 1% group. Compared with the 1% calcium group, 4% calcium animals showed significant elevation of p[AII] levels. A slight, insignificant elevation was observed in 0.05% calcium rats compared with those consuming 1% calcium. A final experiment studied animals on the same calcium intakes (0.05, 1 and 4%), but consuming 0.5% saline in place of water. No differences in p[iCa], p[tCa] or p[AII] were observed in these experiments. However, consumption of saline lead to the expected reduction in p[AII] levels which was absent after 6 months in the earlier studies, indicating that normal levels of p[AII] in saline drinkers after 6 months was not a measurement error.(ABSTRACT TRUNCATED AT 250 WORDS)
钠代谢、钙代谢与肾素 - 血管紧张素系统（RAS）之间的相互作用已得到研究。在大鼠饮用高适口性0.5%氯化钠溶液6个月的实验中，6个月后血浆血管紧张素II（p[AII]）水平与饮用自来水的对照动物无差异。然而，与对照组相比，血浆离子钙（p[iCa]）水平显著降低。在第三组饮用盐水但食用补充钙的食物（钙含量按重量计为2%，而对照组为1%）的动物中，p[AII]显著高于其他两组。进行了进一步实验以研究钙摄入量和p[AII]水平的短期（4周）变化。饮食中钙含量分别为高（4%）、正常（1%）和低（0.05%）。所有动物均饮用自来水。与1%钙组相比，4%钙组的血浆总钙（p[tCa]）和p[iCa]浓度升高。在0.05%钙组中，p[iCa]与1%钙组相比显著降低。与1%钙组相比，4%钙组动物的p[AII]水平显著升高。与摄入1%钙的大鼠相比，0.05%钙组大鼠的p[AII]有轻微但不显著的升高。最后一项实验研究了钙摄入量相同（0.05%、1%和4%）但饮用0.5%盐水而非自来水的动物。在这些实验中，未观察到p[iCa]、p[tCa]或p[AII]有差异。然而，饮用盐水导致p[AII]水平如预期降低，而在早期研究中6个月后未出现这种情况，这表明6个月后饮用盐水的动物中p[AII]的正常水平并非测量误差。（摘要截断于250字）
