title: The method of urinary total kallikrein and prekallikrein measurement, and their urinary excretions in the patients with essential hypertension.
abstract: The method of measurement for urinary total kallikrein (KAL) and preKAL in human was developed, and daily excretions of urinary total KAL, KAL and preKAL were investigated in patients with essential hypertension. Forty microliter of urine samples were incubated with or without 120 micrograms of chymotrypsin-free trypsin for total KAL or KAL, respectively. KAL was measured with direct radioimmunoassay and kininogenase assay. PreKAL was calculated by the subtraction of KAL from total KAL. The subjects of this study included 7 normotensives (NT) and 8 essential hypertensives (EHT). Daily excretions of total KAL, KAL and preKAL were significantly lower in EHT than those in NT. KAL/total KAL ratio, which reflects the conversion rate from preKAL to KAL in the kidney, was not significantly different between EHT and NT. From these results, it is suggested that decreased urinary KAL excretion in EHT is mainly caused by reduced preKAL production rather than the impaired conversion from preKAL to KAL in the kidney. It is emphasized that this method of measurement for urinary total KAL and preKAL may be a very useful tool for research of the renal kallikrein-kinin system.
mesh_terms: D000328:Adult; D000368:Aged; D004789:Enzyme Activation; D006801:Humans; D006973:Hypertension / Q000201:enzymology* / Q000652:urine; D007610:Kallikreins / Q000032:analysis* / Q000652:urine*; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008875:Middle Aged; D011288:Prekallikrein / Q000032:analysis*; D012016:Reference Values
chemical_list: D011288:Prekallikrein; D007610:Kallikreins