Esper E, Barichello A W, Chan E K, Matts J P, Buchwald H
Surgery. 1987 Jul;102(1):39-51.
Partial ileal bypass (PIB) and ingestion of alfalfa are both known to lower plasma cholesterol (C) levels. During an 18-week period, the combined effects of both were studied in four randomized groups of rabbits receiving C-free, hypercholesterolemia-inducing, semisynthetic diets 3 weeks after sham or PIB surgery. The diets, with or without alfalfa, had similar overall compositions of fat, protein, carbohydrate, and fiber. We measured blood C, triglycerides (T), and lipoprotein fractions of both C and T at biweekly intervals. In vivo liver and small-bowel synthesis of C, fatty acids (FA), and nonsaponifiable lipids (NSL) were determined with radioactive 14C-acetate at the end of the study. The results were evaluated by means of analysis of variance using unweighted cell means. The combined PIB and alfalfa modalities significantly lower C levels in serum, plasma, low-density lipoproteins, and high-density lipoproteins by 66%, 71%, 85%, and 35%, respectively. However, due to alfalfa, a significant increase of 49% was observed in plasma T when both treatments were combined. Liver FA synthesis was significantly decreased (65%) with PIB and increased (161%) with alfalfa; when the two treatments are combined, a nonsignificant response was observed. Similarly, this inverse relationship for PIB and alfalfa was seen for C and NSL synthesis. Small-bowel FA synthesis was significantly decreased (72%) by the combination of PIB and alfalfa. We conclude that alfalfa suppresses, in part, the physiologic rebound effect of PIB surgery by increasing hepatic C and NSL synthesis; inversely, PIB surgery inhibits the additive effect in the liver synthesis of FA produced by alfalfa. Alfalfa and PIB alone, and synergistically, decrease total small-bowel lipid synthesis, specifically that of FA. Alfalfa is an effective adjuvant to PIB for reducing total and lipoprotein C fractions.
部分回肠旁路术（PIB）和苜蓿摄入均已知可降低血浆胆固醇（C）水平。在为期18周的时间里，对四组随机分组的兔子进行了研究，这些兔子在假手术或PIB手术后3周接受无胆固醇、诱导高胆固醇血症的半合成饮食。含或不含苜蓿的饮食在脂肪、蛋白质、碳水化合物和纤维的总体组成上相似。我们每两周测量一次血液中的C、甘油三酯（T）以及C和T的脂蛋白组分。在研究结束时，用放射性14C - 乙酸盐测定体内肝脏和小肠中C、脂肪酸（FA）和非皂化脂质（NSL）的合成。结果通过使用未加权单元格均值的方差分析进行评估。PIB和苜蓿联合方式可使血清、血浆、低密度脂蛋白和高密度脂蛋白中的C水平分别显著降低66%、71%、85%和35%。然而，由于苜蓿的存在，两种处理联合时血浆T显著增加了49%。PIB可使肝脏FA合成显著降低（65%），苜蓿则使其增加（161%）；两种处理联合时，观察到的反应不显著。同样，PIB和苜蓿在C和NSL合成方面也呈现这种相反关系。PIB和苜蓿联合可使小肠FA合成显著降低（72%）。我们得出结论，苜蓿通过增加肝脏C和NSL合成部分抑制了PIB手术的生理反弹效应；相反，PIB手术抑制了苜蓿在肝脏FA合成中产生的累加效应。单独使用苜蓿和PIB以及二者协同作用，均可降低小肠总脂质合成，特别是FA的合成。苜蓿是PIB降低总胆固醇和脂蛋白C组分的有效辅助手段。
