Dilger Ryan N, Toue Sakino, Kimura Takeshi, Sakai Ryosei, Baker David H
Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
J Nutr. 2007 Feb;137(2):331-8. doi: 10.1093/jn/137.2.331.
A comparative species investigation of the relative pharmacologic effects of sulfur amino acids was conducted using young chicks, rats, and pigs. Ingestion of excess Met, Cys, or Cys-Cys supplemented at 2.5-, 5.0-, 7.5-, or 10 times the dietary requirement in a corn-soybean meal diet depressed chick growth to varying degrees. Strikingly, ingestion of excess Cys at 30 g/kg Cys (7.5-times the dietary requirement) caused a chick mortality rate of 50% after only 5 d of feeding. Growth was restored and chick mortality was reduced by supplementing diets containing 25 g/kg excess Cys with KHCO3 at 10 g/kg. Additionally, mortality was prevented by supplementing the drinking water of chicks receiving 25 g/kg supplemental Cys with H2O2 (0.05% final concentration). After young rats and pigs consumed excess Cys or Cys-Cys up to 40 g/kg for 14 d, weight gain was severely depressed, but we observed no mortality. An excess of dietary Cys-Cys>or=48 g/kg caused some mortality in rats. Pigs exhibited rapid recovery from growth-depressing excesses of Cys or Cys-Cys. These results lend credence to the acute toxic effects associated with the ingestion of excess sulfur amino acids and highlight the potential for excess dietary cyst(e)ine to be more pernicious than Met in certain species.
利用幼雏、大鼠和猪对含硫氨基酸的相对药理作用进行了一项比较物种研究。在玉米-豆粕日粮中，摄入过量的蛋氨酸（Met）、半胱氨酸（Cys）或胱氨酸（Cys-Cys），添加量为日粮需求量的2.5、5.0、7.5或10倍，会不同程度地抑制雏鸡生长。引人注目的是，摄入30 g/kg Cys（日粮需求量的7.5倍）的过量Cys后，仅喂食5天雏鸡死亡率就达到50%。通过在含25 g/kg过量Cys的日粮中添加10 g/kg的碳酸氢钾（KHCO3），生长得以恢复，雏鸡死亡率降低。此外，通过在饮用水中添加终浓度为0.05%的过氧化氢（H2O2），可防止摄入25 g/kg补充Cys的雏鸡死亡。幼鼠和幼猪摄入高达40 g/kg的过量Cys或Cys-Cys，持续14天后，体重增加受到严重抑制，但未观察到死亡情况。日粮中过量的Cys-Cys≥48 g/kg会导致部分大鼠死亡。猪从Cys或Cys-Cys过量导致的生长抑制中恢复迅速。这些结果证实了摄入过量含硫氨基酸会产生急性毒性作用，并突出了在某些物种中，过量的日粮胱氨酸可能比蛋氨酸更具危害性。
