Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We developed new sensitive direct radioimmunoassay for human plasma renin. Renin was purified from Haas' preparation utilizing a pepstatin-C6-Sepharose affinity chromatography. Antiserum, prepared by immunizing rabbits with the purified renin, was used for the direct radioimmunoassay at a final dilution of 1:30,000. The antibody was specific for human renal and plasma renin, but did not cross-react with cathepsin D, trypsin, or renins of mouse, dog, and rat. Radioimmunoassay was performed by the double antibody technique using the delayed tracer addition method. In this method, a standard curve was obtained over a range from 0.2 to 8.0 ng/ml. The values from our assay correlated well with total renin activity measured as the generation rate of angiotensin I after trypsin activation (r = 0.78, p less than 0.01), but correlated weakly with active renin activity. This finding disclosed that both active and inactive renin were detected by this method. In normal participants, plasma renin concentration determined by direct radioimmunoassay was increased by standing and furosemide injection. The plasma renin concentration determined by direct radioimmunoassay of patients with essential hypertension (0.7 to 1.7 ng/ml) was not significantly different from values in normal controls (0.8 to 1.9 ng/ml). The values were higher in patients with renovascular hypertension (1.6 to 2.7 ng/ml), malignant hypertension (2.8 to 3.4 ng/ml) and Bartter's syndrome (1.8 to 2.5 ng/ml), but lower in patients with primary aldosteronism (0.4 to 0.8 ng/ml) than in normal controls. This newly developed radioimmunoassay for human renin was sensitive enough to estimate the levels of renin in plasma of patients with low renin hypertension. It provides a new tool for the understanding of the renin-angiotensin system under various clinical conditions.
 ...
PMID:A new sensitive direct radioimmunoassay for human plasma renin and its clinical application. 638 35

Plasma levels of kininogen, kallikrein, and prekallikrein were determined in patients with malignant hypertension (MH) and compared to normotensive controls (NC) and patients with mild to moderate essential hypertension (EH). Also, a recently described kinin potentiating factor (KPF) was estimated by dividing the value of kininogen determined by trypsin (Kgn-Try) by that of kininogen determined by human urinary kallikrein (Kgn-HuUk). No significant alterations were detected among plasma values of pre-kallikrein and kallikrein of MH as compared to NC. However, Kgn-HuUK values were significantly lower in MH (1.9 +/- 0.3 micron gLBK/ml) as compared to EH and NC (2.7 +/- 0.1 micron gLBK/ml and 3.0 +/- 0.2 micron gLBK/ml respectively, p less than 0.05). Furthermore, KPF values were also low (p less than 0.05) in MH (1.6 +/- 0.3) when compared with similar values obtained in EH and NC (3.0 +/- 0.2 and 2.8 +/- 0.1, respectively). Adequate control of blood pressure levels for 90 days in MH group caused no significant alterations in plasma levels of kininogen and KPF. It is suggested that diminished kininogen levels as well as a decrease in a kinin potentiation KPF that is generated in plasma by trypsin may be involved in the pathogenesis of human malignant hypertension.
 ...
PMID:Malignant hypertension: a syndrome associated with low plasma kininogen and kinin potentiating factor. 702 21