The kallikrein-kinin system in the kidney.
The kallikrein-kinin system in the kidney.
复制标题
肾脏中的激肽释放酶-激肽系统。
作者：
J. Pisano;J. Corthorn;K. Yates;J. Pierce
为了了解激肽释放酶-激肽系统在肾脏中的作用，需要考虑系统的所有组分及其定位。尿中约有一半的激肽释放酶作为酶原出现在远端小管中。激肽由尿激肽原在远端小管和集合管中形成，尿激肽原在整个小管中发现。尿液中含有的赖氨酰-布兰迪激肽约为缓激肽的两倍。第三种激肽，甲硫氨酰赖氨酰缓激肽，也可以出现在尿液中。它可能是由尿胃蛋白酶产生的，因为激肽主要在酸化尿液中形成，其形成被胃蛋白酶抑制剂抑制。这三种激宁的意义尚不清楚。激肽通常在尿液中缓慢（几小时）被破坏。激肽释放酶、尿激酶原和激酶在调节激肽水平中的重要性需要确定。
To understand the role of the kallikrein-kinin system in the kidney all components of the system and their localization need to be considered. About half the kallikrein in urine occurs as the proenzyme which arises in the distal tubule. Kinins are formed in the distal tubule and collecting duct from urokinnogen which is found throughout the tubule. Urine contains about twice as much lysyl-brandykinin as bradykinin. A third kinin, methionyl-lysyl-bradykinin, also can occur in urine. It is probably produced by uropepsin as the kinin is largely formed in acidified urine and its formation is inhibited by pepstatin. The significance of the three kinins is unknown. Kinins are normally slowly (few hours) destroyed in urine. The importance of kallikrein, urokinogen and kininases in regulating the level of kinins needs to be determined.