Hammond A C, Carlson J R
J Anim Sci. 1980 Jul;51(1):207-14. doi: 10.2527/jas1980.511207x.
Available evidence supports the view that acute bovine pulmonary edema and emphysema (ABPE) is related to ruminal production of 3-methylindole (3MI) from L-tryptophan (TRP). Ruminal production of 3MI is a two-step process involving the conversion of TRP to indoleacetic acid (IAA) followed by decarboxylation of IAA and 3MI. Reduction in ruminal 2MI production by the inhibition of either of these processes may prevent the onset of ABPE. A closed-system, in vitro ruminal fermentation technique was used to screen 27 compounds for their ability to reduce the conversion of TRP to 3MI. Several compounds tended to reduce 3MI production at both 25 and 5 micrograms/ml. Desoxysalinomycin, X-206, chloral hydrate, nigericin, lasalocid, monensin, narasin and salinomycin all reduced 3MI production by more than 80% at 5 micrograms/ml without reducing total VFA production. All of these compounds, except chloral hydrate, are polyether antibiotics. At least part of the inhibition due to monensin and narasin occurs at the level of TRP conversion to IAA.
现有证据支持这样一种观点，即急性牛肺水肿和肺气肿（ABPE）与瘤胃中由L-色氨酸（TRP）产生3-甲基吲哚（3MI）有关。瘤胃中3MI的产生是一个两步过程，包括TRP转化为吲哚乙酸（IAA），随后IAA脱羧生成3MI。通过抑制这两个过程中的任何一个来减少瘤胃中3MI的产生，可能会预防ABPE的发生。采用一种封闭系统的体外瘤胃发酵技术，筛选27种化合物降低TRP转化为3MI的能力。有几种化合物在25微克/毫升和5微克/毫升时都倾向于降低3MI的产生。去氧盐霉素、X-206、水合氯醛、尼日利亚菌素、拉沙洛西、莫能菌素、那拉菌素和盐霉素在5微克/毫升时都能使3MI的产生降低80%以上，且不降低总挥发性脂肪酸的产生。除水合氯醛外，所有这些化合物都是聚醚类抗生素。莫能菌素和那拉菌素的抑制作用至少部分发生在TRP转化为IAA的水平上。
