Blake D A, Burnett L S, Miyasaki B C, Lim H S, King T M
Am J Obstet Gynecol. 1976 Feb 1;124(3):239-44. doi: 10.1016/0002-9378(76)90150-2.
Hypertonic urea solutions (58 per cent weight/volume) were injected rapidly into ten anesthetized rhesus monkeys at a dose of approximately 2 Gm. per kilogram by the intravenous, intraperitoneal, or intra-amniotic routes. An additional monkey received an intra-amniotic dose of 12.5 Gm. per kilogram. A tracer dose 14C-urea was included for measuring absorption and elimination. The following parameters were monitored before and for four hours after urea injection: arterial and cerebrospinal fluid pressures, heart and respiration rates, urine flow, and urea clearance. Serum electolytes, hematocrit and white count, and cumulative urea excretion were measured for one week. Monkeys were observed for three to six months after injection. At doses up to approximately twice the human dose (on a body weight basis) there were no urea-related deaths and no serious side effects noted in any of the experiments. These results support the suggestion that urea is a relatively safe hyperosmolar agent for inducing midtrimester abortions, especially with regard to inadvertent systemic injection.
将高渗尿素溶液（58%重量/体积）以约每公斤2克的剂量通过静脉、腹腔或羊膜腔内途径快速注射到十只麻醉的恒河猴体内。另外一只猴子接受了每公斤12.5克的羊膜腔内注射剂量。加入了示踪剂量的14C-尿素用于测量吸收和消除情况。在注射尿素之前以及之后的四个小时内监测以下参数：动脉压和脑脊液压力、心率和呼吸频率、尿流量以及尿素清除率。在一周内测量血清电解质、血细胞比容和白细胞计数以及尿素累积排泄量。在注射后对猴子进行三到六个月的观察。在剂量高达约人类剂量（按体重计算）的两倍时，在任何实验中均未出现与尿素相关的死亡情况，也未观察到严重的副作用。这些结果支持了以下观点，即尿素是一种相对安全的高渗剂，可用于诱导孕中期流产，特别是在意外全身注射方面。
