Marteau C, Blanc G, Devaux M A, Portugal H, Gerolami A
INSERM U. 260, Faculté de Médecine, Marseille, France.
Dig Dis Sci. 1993 Nov;38(11):2090-7. doi: 10.1007/BF01297090.
In several species, bicarbonate and calcium concentrations of pancreatic juice are known to vary during the different phases of pancreatic secretion. The effects of these variations on the saturation of juice with calcium carbonate, a critical factor for the formation of pancreatic stones, are not known. In this work, we studied the saturation degree of pancreatic juice with calcium carbonate in six unanesthetized beagle dogs equipped with Thomas cannulae during basal secretion and after bolus injections of cerulein (30 ng/kg) or secretin (0.25 units/kg). In the different samples of pure pancreatic juice, pH, PCO2, bicarbonate, and proteins were measured by standard methods. Total calcium (CaT) and ionized calcium (Ca2+) were determined using calcium-specific electrodes. Saturation with calcium carbonate was calculated by reference to the solubility product of calcite at 37 degrees C. Almost all the samples were found to be supersaturated with calcium carbonate but large variations of the saturation index were observed. In basal samples, obtained during periods of low secretion rate, the mean saturation index (3.35 +/- 3.01) was significantly lower than under secretion (12.10 +/- 5.14) or cerulein (18.01 +/- 8.42). This low basal saturation index, in spite of a high Ca2+ content, was explained by a low bicarbonate concentration (37.6 +/- 18.9 mmol/liter) and a high PCO2 (13.4 +/- 7.5 kPa). In contrast, in juice obtained after hormonal stimulation, PCO2 (4.8 +/- 1.6 kPa) was similar to plasma PCO2 (5.5 +/- 1.2 kPa).(ABSTRACT TRUNCATED AT 250 WORDS)
在多个物种中，已知胰液中的碳酸氢盐和钙浓度在胰腺分泌的不同阶段会发生变化。这些变化对胰液中碳酸钙饱和度（胰腺结石形成的关键因素）的影响尚不清楚。在本研究中，我们在六只配备托马斯套管的未麻醉比格犬的基础分泌期以及推注雨蛙素（30 ng/kg）或促胰液素（0.25 单位/kg）后，研究了胰液中碳酸钙的饱和度。通过标准方法测量纯胰液不同样本中的pH、PCO₂、碳酸氢盐和蛋白质。使用钙特异性电极测定总钙（CaT）和离子钙（Ca²⁺）。通过参考37℃方解石的溶度积计算碳酸钙饱和度。几乎所有样本均被发现碳酸钙过饱和，但观察到饱和度指数有很大差异。在低分泌率时期获得的基础样本中，平均饱和度指数（3.35±3.01）显著低于分泌期（12.10±5.14）或雨蛙素刺激后（18.01±8.42）。尽管Ca²⁺含量高，但基础饱和度指数低是由于碳酸氢盐浓度低（37.6±18.9 mmol/升）和PCO₂高（13.4±7.5 kPa）。相反，在激素刺激后获得的胰液中，PCO₂（4.8±1.6 kPa）与血浆PCO₂（5.5±1.2 kPa）相似。（摘要截断于250字）
