Wachenheim D E, Blythe L L, Craig A M
College of Veterinary Medicine, Oregon State University, Corvallis 97331-4802.
Vet Hum Toxicol. 1992 Dec;34(6):513-7.
An in vitro assay was used to examine biotransformation of toxic Senecio jacobaea pyrrolizidine alkaloids (PA) in ovine, bovine, and caprine rumen contents. Pyrrolizidine alkaloids were analysed by high performance liquid chromatography, and the rates of the alkaloid biotransformation were determined. The microbiological "Most Probable Numbers" technique was also used, in combination with thin-layer chromatography, to estimate relative numbers of rumen PA-biotransforming bacteria in the same samples. Pyrrolizidine alkaloids were biotransformed at average rates of 2.9 micrograms/ml/h (bovine), 25.6 micrograms/ml/h (caprine), and 19.2 micrograms/ml/h (ovine). Estimates of numbers of PA-biotransforming bacteria were 1.1 x 10(7) bacteria/ml rumen contents (bovine), 2.4 x 10(7) bacteria/ml (caprine), and 3.0 x 10(7) bacteria/ml (ovine). This project is among the first to quantitate rates of PA biotransformation in rumen contents and to identify caprine and bovine, in addition to ovine, rumen PA-biotransforming activity, as well as to estimate the actual numbers of PA-biotransforming bacteria in rumen contents.
采用体外试验检测了绵羊、牛和山羊瘤胃内容物中毒性千里光属吡咯里西啶生物碱（PA）的生物转化。通过高效液相色谱法分析吡咯里西啶生物碱，并测定生物碱的生物转化速率。还采用微生物“最大可能数”技术结合薄层色谱法，估计相同样本中瘤胃PA生物转化细菌的相对数量。吡咯里西啶生物碱的平均生物转化速率分别为：牛2.9微克/毫升/小时、山羊25.6微克/毫升/小时、绵羊19.2微克/毫升/小时。PA生物转化细菌数量估计为：牛瘤胃内容物中每毫升1.1×10⁷个细菌、山羊每毫升2.4×10⁷个细菌、绵羊每毫升3.0×10⁷个细菌。该项目首次对瘤胃内容物中PA生物转化速率进行了定量，并确定了除绵羊外，山羊和牛瘤胃中的PA生物转化活性，同时还估计了瘤胃内容物中PA生物转化细菌的实际数量。
