Ethanol/lipid metabolism, dysfunction of ion transport, and pathogenesis of alcoholic pancreatitis

1. 在日本慢性胰腺炎患者中检测了CFTR（囊性纤维化跨膜传导调节因子）的突变和多态性（TG重复、poly T、M470V、Q1352H、R1453W）。没有检测到囊性纤维化引起的突变。酒精性胰腺炎中基因型TG（12/12）的发生率较高。基因型V470/V470在特发性胰腺炎中发生率较高。为了估计CFTR的Cl^-通道功能，我们建立了“手指汗液氯化物试验”来测量无意识汗液中的Cl^-浓度，该方法是用拇指拿着一个含有100 μl水的小管收集汗液，用排汗仪测量出汗率。样品中的氯含量可用毛细管电泳或更容易的用高灵敏度电极测定。在囊性纤维化模型ΔF小鼠中分离的小叶间胰管段中，采用光微灌注法检测了顶端膜Na^+-H^+交换（NHE）的活性。ΔF/ΔF导管顶端NHE活性显著升高，可能导致胰液pH降低。研究了一系列短链醇（甲醇、乙醇、丙醇和丁醇）对豚鼠小叶间胰管段camp刺激的液体分泌和细胞内Ca^<2+>浓度的影响。甲醇和乙醇增强体液分泌，导致细胞内Ca^<2+>短暂升高。相反，丙醇和丁醇抑制液体分泌，降低细胞内Ca^<2+>。这种“切断效应”表明醇类直接作用于胰管细胞的某些离子通道。

1. Mutations and polymorphisms (TG repeats, poly T, M470V, Q1352H, R1453W) of CFTR (cystic fibrosis transmembrane conductance regulator) were examined in Japanese patients with chronic pancreatitis. None of the cystic fibrosis-causing mutations were detected. Frequency of the genotype TG(12/12) was higher in alcoholic pancreatitis. Frequency of the genotype V470/V470 was higher in idiopathic pancreatitis.2. To estimate CFTR Cl^- channel function, we established "finger sweat chloride test" to measure Cl^- concentration in insensible sweat, which sweat is collected by holding a small tube containing 100 μl water with the thumb and the sweat rate is measured by a perspiration meter. The Cl^- content in the sample is measured by capillary electrophoresis or more easily by a highly sensitive electrode.3. The activity of Na^+-H^+ exchange (NHE) in the apical membrane was examined in luminally-microperfused interlobular pancreatic duct segments isolated from ΔF mice, a cystic fibrosis model. The apical NHE activity significantly increased in ΔF/ΔF ducts, which may cause pH decrease of pancreatic juice.4. Effects of a series of short-chain alcohols (methanol, ethanol, propanol, and butanol) on cAMP-stimulated fluid secretion and intracellular Ca^<2+> concentration were examined in interlobular pancreatic duct segments isolated from guinea-pig. Methanol and ethanol enhanced fluid secretion and caused a transient increase of intracellular Ca^<2+>. On the contrary, propanol and butanol inhibited fluid secretion and lowered intracellular Ca^<2+>. This "cut-off effect" suggests alcohols act directly on some ion channels of pancreatic duct cells.