Ramsay D J, Reid I A, Brown C
Endocrinology. 1979 Oct;105(4):947-51. doi: 10.1210/endo-105-4-947.
Dogs with chronically implanted third ventricular cannulae showed significant drinking responses to central injections of angiotensin II and tetradecapeptide renin substrate (TDP). The threshold dose for angiotensin II was 1 pmol and for TDP was 70 pmol. Although central injections of TDP led to drinking and appearance of angiotensin II in cerebrospinal fluid, renin substrate prepared from dog cerebrospinal fluid had no effect. The dipsogenic action of TDP was blocked by prior administration of converting enzyme inhibitor SQ20881 (P less than 0.01) but was not affected by either pepstatin or N-acetyl-pepstatin. Thus, converting enzyme acts directly on TDP to produce angiotensin I and then angiotensin II. The results of the present study do not provide evidence for the presence of an enzyme in the brain with renin-like activity.
长期植入第三脑室套管的狗对脑室内注射血管紧张素II和十四肽肾素底物（TDP）表现出明显的饮水反应。血管紧张素II的阈值剂量为1皮摩尔，TDP的阈值剂量为70皮摩尔。虽然脑室内注射TDP会导致饮水并使脑脊液中出现血管紧张素II，但从狗脑脊液中制备的肾素底物却没有作用。预先给予转化酶抑制剂SQ20881可阻断TDP的致渴作用（P<0.01），但胃蛋白酶抑制剂或N-乙酰胃蛋白酶抑制剂对其没有影响。因此，转化酶直接作用于TDP以产生血管紧张素I，进而产生血管紧张素II。本研究结果并未提供脑内存在具有肾素样活性的酶的证据。
