Jackson J A, Yates S G, Powell R G, Hemken R W, Bush L P, Boling A, Zavos P M, Siegel M R
Department of Animal Sciences, University of Kentucky, Lexington 40546-0215.
Drug Chem Toxicol. 1989 Jun;12(2):147-64. doi: 10.3109/01480548908999151.
Ethanol and ethanol-water extracts of endophyte-infected tall fescue seed were effective for extracting toxin(s) responsible for feed intake and average daily weight gain (ADG) depression in Sprague Dawley rats. Although the ethanol extract of endophyte-infected seed depressed serum prolactin (Prl) concentrations, the data were less reflective of overall toxicity than feed intake and weight gain. Inclusion of commercially available ergonovine maleate, ergocryptine and ergotamine tartrate had no effect on rat feed intake, ADG or serum Prl at the levels tested. Dietary addition of a recombination of hexane, ethanol and ethanol-water extracts caused a toxicity response (depressed feed intake, ADG, and serum Prl) equivalent to that of the whole seed. The toxic factor(s) were extracted primarily in more polar solvents such as ethanol and ethanol-water. Rat assays can be used successfully in lieu of cattle assays as a routine evaluation of toxic components in endophyte-infected tall fescue. However, species differences dictate that eventually all suspected toxins be evaluated in the bovine.
感染内生真菌的高羊茅种子的乙醇提取物以及乙醇 - 水提取物，对于提取导致斯普拉格 - 道利大鼠采食量和平均日增重（ADG）下降的毒素有效。虽然感染内生真菌种子的乙醇提取物会降低血清催乳素（Prl）浓度，但与采食量和体重增加相比，这些数据对整体毒性的反映较弱。在所测试的水平下，添加市售马来酸麦角新碱、麦角隐亭和酒石酸麦角胺对大鼠采食量、ADG或血清Prl没有影响。在日粮中添加己烷、乙醇和乙醇 - 水提取物的组合会引起与整粒种子相当的毒性反应（采食量、ADG和血清Prl下降）。有毒因子主要在极性更强的溶剂如乙醇和乙醇 - 水中被提取出来。大鼠试验可以成功地替代牛试验，作为对感染内生真菌的高羊茅中有毒成分的常规评估方法。然而，物种差异表明最终所有可疑毒素都应在牛身上进行评估。
