Yelverton C C, Roller M H, Swanson R N
Am J Vet Res. 1975 Feb;36(2):191-2.
Eight pregnant Southdown ewes were treated (by drench) with 12.5 ml of 3.3 M urea solution per kilogram of body weight, and ammonium nitrogen concentrations of blood and tissues of these ewes and their fetuses were measured and compared with those of control ewes (given water by drench) and their fetuses. Blood ammonium nitrogen (BAN) and tissue ammonium nitrogen (TAN) concentrations for liver, kidney, spleen, and muscle of ewes and fetuses were determined by an ion-exchange procedure. Samples of blood were collected before treatment, at 30, 90 and 150 minutes after treatment, and at death of the dam. The principal ewes had increasing BAN concentrations with time after drench, and their fetuses had significantly greater (P less than 0.01) BAN concentrations than fetuses from control ewes. All fetuses were alive after death of the dams and had lower TAN values than their dams. The differences in ammonia concentrations between ewes and fetuses were larger in the principal group than in the control group. Except for ewe muscle and fetal liver, all tissues of principals had significantly greater (P less than 0.01) TAN concentrations than those of controls. Muscle of principal ewes and hepatic tissues of their fetuses had greater (P less than 0.05) TAN concentrations than those of control ewes and their fetuses.
八只怀孕的南丘母羊每千克体重经口灌服12.5毫升3.3 M尿素溶液进行处理，测定这些母羊及其胎儿血液和组织中的铵态氮浓度，并与对照母羊（经口灌服水）及其胎儿的铵态氮浓度进行比较。采用离子交换法测定母羊和胎儿肝脏、肾脏、脾脏及肌肉的血液铵态氮（BAN）和组织铵态氮（TAN）浓度。在处理前、处理后30分钟、90分钟和150分钟以及母羊死亡时采集血样。主要母羊灌服后BAN浓度随时间增加，其胎儿的BAN浓度显著高于对照母羊的胎儿（P<0.01）。所有胎儿在母羊死亡后仍存活，其TAN值低于母羊。主要组母羊和胎儿之间的氨浓度差异大于对照组。除母羊肌肉和胎儿肝脏外，主要组所有组织的TAN浓度均显著高于对照组（P<0.01）。主要母羊的肌肉及其胎儿的肝脏组织的TAN浓度高于对照母羊及其胎儿（P<0.05）。
