Marteau C, Silviani V, Ducroc R, Crotte C, Gerolami A
INSERM U 260, Faculte de Médecine, Marseille, France.
Dig Dis Sci. 1995 Nov;40(11):2336-40. doi: 10.1007/BF02063234.
The finding of a high PCO2 in basally secreted pancreatic juice of man and dog raises the hypothesis of proton secretion from ductal epithelial cells presumably through a Na+/H+ exchanger. To test this possibility, H+ luminal secretion and Na+ movements were measured in vitro on samples of bovine pancreatic ducts mounted in Ussing-type chambers. The rate of luminal acidification measured by the pH stat method, using bicarbonate-free media gassed with 100% O2, reached 2.75 muEq/cm2/hr. Proton secretion was blocked in the presence of 1 nM amiloride or in the absence of Na+ (replaced by choline) in the mucosal solution. Study of transepithelial 22Na fluxes in short-circuited tissue, bathed on both sides by control Ringer solution, gassed by 95% O2-5% CO2 demonstrated a net sodium transport from the mucosal to the interstitial side of the duct (net 22Na flux = 3.23 +/- 0.8 muEq/cm2/hr). This net sodium transport was electroneutral and blocked by mucosal amiloride (0.5-1 mM/liter) or by interstitial ouabain (1 mM/liter). These results are consistent with the existence of a Na+/H+ exchanger on the luminal side of the bovine main pancreatic duct.
在人和狗基础分泌的胰液中发现高PCO₂，这引发了一种假说，即导管上皮细胞可能通过Na⁺/H⁺交换体分泌质子。为了验证这种可能性，在安装于Ussing型小室中的牛胰导管样本上，体外测量了H⁺向管腔的分泌和Na⁺的转运。使用不含碳酸氢盐、用100% O₂充气的培养基，通过pH计法测量的管腔酸化速率达到2.75 μEq/cm²/小时。在黏膜溶液中存在1 nM氨氯吡脒或不存在Na⁺（用胆碱替代）时，质子分泌被阻断。在两侧用对照林格溶液冲洗、用95% O₂ - 5% CO₂充气的短路组织中，对跨上皮²²Na通量的研究表明，有净钠从导管的黏膜侧向间质侧转运（净²²Na通量 = 3.23 ± 0.8 μEq/cm²/小时）。这种净钠转运是电中性的，并被黏膜氨氯吡脒（0.5 - 1 mM/升）或间质哇巴因（1 mM/升）阻断。这些结果与牛主胰导管管腔侧存在Na⁺/H⁺交换体一致。
