Pharmacokinetic comparison of gossypol isomers in cattle: transfer from diet to plasma and degradation by rumen microbes

棉酚旋光异构体在牛体内代谢动力学研究:从日粮向血浆中转移及瘤胃微生物的降解作用(英文)

A pharmacokinetic comparison of gossypol isomers in cattle was made by investigating their transfer from ingested food to plasma and their degradation by rumen microbes. The gossypol isomers in whole cottonseed, plasma, and rumen fluid were determined by high-performance liquid chromatography(HPLC). The intakes of(+)-and(-)-gossypol by cows on three farms were about 5.6–8.5 and 3.8–5.9 g/(d·herd), respectively. The plasma gossypol concentrations increased as ingestion increased and ranged from 0.31 to 0.48 μg/ml for the(+) form and from 0.39 to 0.59 μg/ml for the(-) form. The(+) form was slightly predominant(58.8%–59.8%) in the gossypol ingested by the cows, whereas the(-) form predominated(54.6%–55.9%) in the plasma. An in vitro study showed that at 6 h, 67.4% and 85.7% of the(-)-gossypol were degraded in 500 and 1000 μg/g treatment groups, respectively, and these increased to 83.6% and 92.5%, respectively, at 12 h. The regularity of the degradation of(+)-gossypol was similar to that of(-)-gossypol. These results showed that(-)-gossypol may be more persistent than(+)-gossypol in plasma, and that the degradation of the gossypol isomers in the rumen is rapid and not enantioselective in cattle.

目的:比较研究棉酚旋光异构体从日粮向血浆中转移以及瘤胃微生物的降解作用。创新点:从饲粮向血浆中吸收代谢以及瘤胃微生物降解角度揭示了棉酚旋光异构体在牛体内代谢差异,为棉酚毒理学评价、棉籽类产品在畜牧生产中合理应用提供科学依据。方法:利用高效液相色谱法(HPLC)测定全棉籽、血浆及瘤胃发酵液中棉酚旋光异构体含量。结论:三个调研牛场奶牛日粮右旋、左旋棉酚摄入量分别在5.6~8.5和3.8~5.9g/(d·herd)之间。血浆棉酚含量与日粮棉酚摄入量呈正相关,右旋、左旋棉酚浓度分别在0.31~0.48和0.39~0.59μg/ml之间。奶牛摄入棉酚中右旋棉酚比率(58.8%~59.8%)高于左旋棉酚,血浆中左旋棉酚比率(54.6%~55.9%)高于右旋棉酚。体外静态培养试验发现:500和1000μg/g组左旋棉酚的降解率在6小时后分别为67.4%和85.7%,12小时后降解率分别升高到83.6%和92.5%;同时,棉酚旋光异构体之间降解规律相似。结果表明:相比于右旋棉酚,左旋棉酚在奶牛体内吸收率更高,瘤胃微生物对棉酚旋光异构体的降解没有选择性。