Berg T, Johansen L, Nustad K
Am J Physiol. 1985 Dec;249(6 Pt 2):H1134-42. doi: 10.1152/ajpheart.1985.249.6.H1134.
Enzymatic activity of submandibular gland (SG) kallikrein released into saliva and blood was studied at rest and after autonomic nerve stimulation. Kallikrein was measured by an immunometric assay that allows measurement of immunoreactive kallikrein in complex with inhibitors as well as simultaneous determination of kallikrein enzymatic activity. Measurements using the chromogenic substrate S2266 gave identical results to the natural substrate kininogen. Endogenous SG kallikrein secretory rate was, at rest, 0.9 +/- 0.1 ng/min. Kallikrein secretion into blood in response to autonomic nerve stimulation paralleled that into saliva, and secretion was greatly enhanced by alpha-adrenergic stimulation. In plasma, kallikrein was bound to several inhibitors that completely or partially blocked the enzyme activity. In arterial and SG venous control plasma, 93 +/- 3 and 72 +/- 10% inhibition of kallikrein enzyme activity was observed, respectively. Sympathetic stimulation after administration of a beta-adrenergic blocker increased kallikrein enzyme activity 62 and 11 times in arterial and SG venous plasma, respectively, with a corresponding 78 +/- 8 and 70 +/- 8% inhibition of kallikrein enzyme activity. A fraction containing kallikrein resembling "free kallikrein" was always present in plasma.
研究了在静息状态以及自主神经刺激后，释放到唾液和血液中的下颌下腺（SG）激肽释放酶的酶活性。采用免疫测定法测量激肽释放酶，该方法能够测量与抑制剂结合的免疫反应性激肽释放酶，并同时测定激肽释放酶的酶活性。使用显色底物S2266进行的测量结果与天然底物激肽原相同。静息状态下，内源性SG激肽释放酶的分泌速率为0.9±0.1 ng/分钟。自主神经刺激后，激肽释放酶向血液中的分泌与向唾液中的分泌情况相似，且α-肾上腺素能刺激可大大增强其分泌。在血浆中，激肽释放酶与几种抑制剂结合，这些抑制剂会完全或部分阻断酶的活性。在动脉血和SG静脉对照血浆中，分别观察到激肽释放酶活性受到93±3%和72±10%的抑制。在给予β-肾上腺素能阻滞剂后进行交感神经刺激，动脉血和SG静脉血浆中的激肽释放酶活性分别增加了62倍和11倍，同时激肽释放酶活性受到相应的78±8%和70±8%的抑制。血浆中始终存在一部分类似于“游离激肽释放酶”的激肽释放酶。
