Ohshima A, Cohen B I, Ayyad N, Mosbach E H
Department of Surgery, Beth Israel Medical Center, New York, New York 10003, USA.
Lipids. 1996 Sep;31(9):949-54. doi: 10.1007/BF02522688.
Dietary fat has been found to alter the incidence of cholesterol gallstones in hamsters: butterfat intensifies while safflower oil reduces lithiasis. WE not report how dietary fat affects bile flow and biliary lipid secretion in this model. Male hamsters were fed one of three experimental diets: a control diet (containing 0.3% cholesterol); control diet + 4.0% butterfat; or control diet + 4.0% safflower oil. After three weeks, bile samples were collected via an external biliary fistula. The endogenous bile acid pool was depleted for 120 min followed by increasing rates of taurocholate infusion for 160 min. Basal secretion of biliary lipids was measured during the bile acid depletion period. Basal bile flow and bile acid output were not significantly different in the three groups. Dietary butterfat increased basal cholesterol output compared to the control diet (0.037 vs. 0.025 mumol/min.kg, respectively); safflower oil did not change cholesterol output (0.027 mumol/min.kg). Hamsters fed butterfat or safflower oil secreted more phospholipid (0.171 and 0.178 mumol/min.kg, respectively) than controls (0.131 mumol/min.kg). The cholesterol/phospholipid output ratio of the butterfat group was higher than the safflower oil group (0.220 vs. 0.153, respectively). Effects of dietary fat on several relationships between file flow and biliary lipid secretion were analyzed by linear regression using the data for the entire bile collection period (bile acid depletion and taurocholate infusion). Butterfat and safflower oil did not change either bile acid dependent or bile acid independent bile flow. Hamsters fed butterfat had a higher linkage coefficient (slope) of cholesterol vs. bile acid output than the safflower oil group (0.023 vs. 0.009, respectively). The linkage coefficient of phospholipid vs. bile acid output of the butterfat group was higher than the controls (0.278 vs. 0.185, respectively). In summary, butterfat induced a high cholesterol and phospholipid secretion with a high cholesterol/phospholipid output ratio; safflower oil induced a high phospholipid secretion with a low cholesterol/phospholipid output ratio. Butterfat and safflower oil have different effects on biliary lipid secretion. These differences in biliary lipid secretion may explain, in part, how butterfat and safflower oil differ in affecting gallstone formation in hamsters.
乳脂会加剧而红花油会降低结石形成。我们未报告在此模型中膳食脂肪如何影响胆汁流动和胆汁脂质分泌。雄性仓鼠被喂食三种实验饮食之一：对照饮食（含0.3%胆固醇）；对照饮食 + 4.0%乳脂；或对照饮食 + 4.0%红花油。三周后，通过外部胆管瘘收集胆汁样本。内源性胆汁酸池排空120分钟，随后以递增速率输注牛磺胆酸盐160分钟。在胆汁酸排空期测量胆汁脂质的基础分泌。三组的基础胆汁流动和胆汁酸输出无显著差异。与对照饮食相比，膳食乳脂增加了基础胆固醇输出（分别为0.037与0.025 μmol/分钟·千克）；红花油未改变胆固醇输出（0.027 μmol/分钟·千克）。喂食乳脂或红花油的仓鼠分泌的磷脂比对照组更多（分别为0.171和0.178 μmol/分钟·千克，而对照组为0.131 μmol/分钟·千克）。乳脂组的胆固醇/磷脂输出比高于红花油组（分别为0.220与0.153）。使用整个胆汁收集期（胆汁酸排空和牛磺胆酸盐输注）的数据，通过线性回归分析膳食脂肪对胆汁流动与胆汁脂质分泌之间几种关系的影响。乳脂和红花油均未改变胆汁酸依赖性或胆汁酸非依赖性胆汁流动。喂食乳脂的仓鼠胆固醇与胆汁酸输出的连锁系数（斜率）高于红花油组（分别为0.023与0.009）。乳脂组磷脂与胆汁酸输出的连锁系数高于对照组（分别为0.278与0.185）。总之，乳脂诱导高胆固醇和磷脂分泌且胆固醇/磷脂输出比高；红花油诱导高磷脂分泌且胆固醇/磷脂输出比低。乳脂和红花油对胆汁脂质分泌有不同影响。胆汁脂质分泌的这些差异可能部分解释了乳脂和红花油在影响仓鼠胆结石形成方面的差异。
