Hirata Y, Tomita M, Fujita T, Ikeda M
Acta Endocrinol (Copenh). 1986 Jan;111(1):140-4. doi: 10.1530/acta.0.1110140.
The submandibular gland (SMG) of the rat contains tonin, an enzyme of serine proteases, which specifically cleaves angiotensinogen and angiotensin I to yield angiotensin II directly. Using a specific RIA for rat tonin, the present study was performed to examine the concentrations of immunoreactive (IR) tonin in SMG of normal Wistar male rats with various ages, those in SMG and saliva of normal adult males and females, and also its SMG levels of castrated males and testosterone-treated females. The concentrations of IR-tonin in SMG of immature 4 week old male rats were very low but rose exponentially with increasing age to reach adult levels (3-6 micrograms/mg wet tissue) in male rats after 6 week old or more. SMG of the adult male rat contained 10-fold more IR-tonin than that of the female rat and male saliva contained 5-fold more IR-tonin than that of females. The concentrations of SMG IR-tonin in the castrated males fell to about one-tenth the levels of normal males, whereas SMG IR-tonin levels in the testosterone-treated females increased about ten times more than those of normal females. These data confirm the sexual dimorphism of rat SMG with respect to the concentrations of tonin and indicate that androgens play an important role in regulating the synthesis and/or storage of tonin in rat SMG. It is also suggested that tonin is secreted into saliva in concentrations reflecting its SMG levels. However, biological significance of tonin in SMG and saliva remains obscure.
大鼠的颌下腺（SMG）含有血管紧张肽原酶，一种丝氨酸蛋白酶，它能特异性地切割血管紧张素原和血管紧张素I，直接产生血管紧张素II。本研究使用针对大鼠血管紧张肽原酶的特异性放射免疫分析（RIA），检测了不同年龄正常Wistar雄性大鼠颌下腺中免疫反应性（IR）血管紧张肽原酶的浓度、正常成年雄性和雌性大鼠颌下腺和唾液中IR血管紧张肽原酶的浓度，以及去势雄性大鼠和接受睾酮治疗的雌性大鼠的颌下腺中该酶的水平。4周龄未成熟雄性大鼠颌下腺中IR血管紧张肽原酶的浓度非常低，但随着年龄增长呈指数上升，在6周龄及以上的雄性大鼠中达到成年水平（3 - 6微克/毫克湿组织）。成年雄性大鼠颌下腺中IR血管紧张肽原酶的含量比雌性大鼠多10倍，雄性唾液中IR血管紧张肽原酶的含量比雌性多5倍。去势雄性大鼠颌下腺中IR血管紧张肽原酶的浓度降至正常雄性大鼠的约十分之一，而接受睾酮治疗的雌性大鼠颌下腺中IR血管紧张肽原酶的水平比正常雌性大鼠增加了约10倍。这些数据证实了大鼠颌下腺在血管紧张肽原酶浓度方面存在性别差异，并表明雄激素在调节大鼠颌下腺中血管紧张肽原酶的合成和/或储存方面发挥着重要作用。还表明血管紧张肽原酶以反映其在颌下腺水平的浓度分泌到唾液中。然而，血管紧张肽原酶在颌下腺和唾液中的生物学意义仍不清楚。
