人类是排尿素动物,并依赖合成尿素来排出氮.尿素循环(图192-1)是体内尿素净形成的唯一途径,为此需有5种酶,才能相继合成氨甲酰磷酸,瓜氨酸、精氨琥珀酸、精氨酸和尿素.此途径如有窒碍,即是氨潴积.与此伴随的临床改变有某些共同特征,如智力迟钝、神经系统严重功能失常.上述5个步骤中,每一步都可因遗传病而发生阻滞,下文将就此作一扼述.此外,还曾发现一例缺乏促使乙酰谷氨酸形成的N-乙酰谷氨酸合成 Humans are urea-urea-producing animals and rely on synthetic urea to expel nitrogen. The urea cycle (Figure 192-1) is the only way for the net formation of urea in the body, requiring five enzymes to synthesize carbamoyl phosphate, citrulline, Arginine succinate, arginine and urea .If this pathway is obstructed, that is, ammonia accumulation.With this accompanying clinical changes have some common features, such as mental retardation, serious nervous system dysfunction.In the above five steps , Each step can be blocked due to genetic disease, the following will make a summary of this.In addition, it has also been found in a case of lack of N-acetyl glutamate to promote the formation of acetyl glutamate synthesis