Atillasoy E, Fein B, Weinstein I B, Holt P R
Department of Medicine, St. Luke's-Roosevelt Hospital Center, New York, New York 10025, USA.
Cancer Epidemiol Biomarkers Prev. 1995 Oct-Nov;4(7):795-6.
Growth factors are known to stimulate colonic proliferation via activation of protein kinase C by production of diacylglycerol (DAG) from membrane phosphatidyl inositol. Previous studies from our laboratories have shown that fecal bacteria can produce and metabolize DAG and that DAG can be absorbed by colonocytes, and thus might contribute to neoplasia. Calcium is a putative chemopreventive agent, and we have shown that calcium administration reduces fecal DAG concentrations, as well as rectal proliferation in patients after jejuno-ileal bypass surgery. The present study in normal volunteers eating self-selected diets demonstrates that fecal DAG concentrations are very constant with a coefficient of variation from 6.7 to 10.2%. Calcium administration showed a trend to reduce fecal DAG by 11% (P < 0.08). We conclude that fecal DAG levels can be determined in individuals on a self-selected diet from a single stool determination. If the trend to reduce fecal DAG by calcium is verified in more extensive studies, then the effects of calcium used in chemopreventive might, in part, reflect changes in the luminal lipid content.
已知生长因子可通过由膜磷脂酰肌醇产生二酰基甘油（DAG）来激活蛋白激酶C，从而刺激结肠增殖。我们实验室先前的研究表明，粪便细菌能够产生和代谢DAG，并且DAG可被结肠细胞吸收，因此可能与肿瘤形成有关。钙是一种公认的化学预防剂，我们已经表明，给予钙可降低粪便DAG浓度，以及空肠回肠旁路手术后患者的直肠增殖。本研究针对食用自选饮食的正常志愿者开展，结果表明粪便DAG浓度非常稳定，变异系数为6.7%至10.2%。给予钙有使粪便DAG降低11%的趋势（P < 0.08）。我们得出结论，对于食用自选饮食的个体，通过单次粪便检测即可测定粪便DAG水平。如果在更广泛的研究中证实了钙降低粪便DAG的趋势，那么化学预防中使用钙的效果可能部分反映了肠腔脂质含量的变化。
