Rege R V, Dawes L G, Moore E W
Department of Surgery, Northwestern University Medical School Chicago, IL 60611.
J Lab Clin Med. 1989 May;113(5):642-50.
We performed studies involving large incremental additions of calcium to bile to examine the degree of CaCO3 supersaturation that can be achieved in bile, as compared with that in simple NaCl-NaHCO3 solutions. The addition of CaCl2 to bile increased total and free ionized calcium by from four to 12 times their original values and by from two to three times the highest concentrations encountered in bile in vivo. The increase in [Ca++] resulted in fourfold to 12-fold increases in the saturation indexes of bile, with the saturation index reaching as high as 73.4 in a common duct sample. Despite the markedly elevated CaCO3 saturation indexes, evidence of CaCO3 precipitation was not observed in either common duct or gallbladder bile over a 24-hour period. For comparison, calcium added to NaCl-NaHCO3 solutions resulted in the precipitation of CaCO3 within 4 hours if saturation indexes were greater than 12. These results indicate that native bile contains potent antinucleating factors that markedly inhibit CaCO3 precipitation, and they confirm our previous in vivo observations in canine common duct bile.
我们进行了一系列研究，向胆汁中大量逐步添加钙，以研究与简单的NaCl-NaHCO₃溶液相比，胆汁中可实现的碳酸钙过饱和度。向胆汁中添加氯化钙使总钙和游离钙离子浓度增加了4至12倍，是体内胆汁中所遇最高浓度的2至3倍。[Ca++]的增加导致胆汁饱和指数增加了4至12倍，在一个胆总管样本中，饱和指数高达73.4。尽管碳酸钙饱和指数显著升高，但在24小时内，胆总管或胆囊胆汁中均未观察到碳酸钙沉淀的迹象。作为对比，如果向NaCl-NaHCO₃溶液中添加钙，当饱和指数大于12时，4小时内就会出现碳酸钙沉淀。这些结果表明，天然胆汁含有能显著抑制碳酸钙沉淀的有效抗成核因子，这也证实了我们之前在犬类胆总管胆汁中的体内观察结果。
