Lis M, Boucher R, Chrétien M, Genest J
Am J Physiol. 1977 May;232(5):E522-5. doi: 10.1152/ajpendo.1977.232.5.E522.
Tonin, an enzyme present in rat submaxillary gland, converts angiotensin I to angiotensin II and is able to form angiotensin II directly from renin substrates. This enzyme was previously shown to be different from renin, tissue isorenins, and angiotensin I converting enzyme. The specific activity of tonin in rat submaxillary gland increases with the age of the animal and is much higher in male than in female rats; this sex difference is apparent from 60 to 70 days of age. There is a sharp drop of tonin activity in hypophysectomized animals, whereas adrenalectomy, thyroidectomy, and gonadectomy have have little effect. The marked increase in tonin activity was observed in animals bearing MtT-F4 transplantable tumors known to produce ACTH, prolactin, and growth hormone. Tonin specific activity in hypophysectomized male rats is restored to control levels by combined treatment with growth hormone and testosterone. Prolactin alone or in combination with testosterone, as well as transplanted pituitaries, has no effect in hypophysectomized animals. There is a significant specific binding of 125I-labeled growth hormone to isolated membranes of rat submaxillary gland.
托宁是一种存在于大鼠下颌下腺的酶，它能将血管紧张素I转化为血管紧张素II，并且能够直接从肾素底物形成血管紧张素II。先前已证明这种酶不同于肾素、组织异肾素和血管紧张素I转换酶。大鼠下颌下腺中托宁的比活性随动物年龄增长而增加，且在雄性大鼠中比雌性大鼠高得多；这种性别差异在60至70日龄时明显。垂体切除的动物中托宁活性急剧下降，而肾上腺切除、甲状腺切除和性腺切除的影响很小。在携带已知能产生促肾上腺皮质激素、催乳素和生长激素的MtT - F4可移植肿瘤的动物中观察到托宁活性显著增加。垂体切除的雄性大鼠中托宁的比活性通过生长激素和睾酮联合治疗恢复到对照水平。单独的催乳素或与睾酮联合使用，以及移植的垂体，对垂体切除的动物没有影响。125I标记的生长激素与大鼠下颌下腺分离膜存在显著的特异性结合。
