Increased urinary kallikrein excretion in young borderline hypertensive patients.

Urinary kallikrein excretion was measured in 46 young patients with borderline hypertension and 28 age-matched normotensive subjects. Hypertensives excreted greater amounts of kallikrein than normotensives (2.31±0.20 units/day vs. 1.56±0.17 units/day, p<0.01). Plasma renin activity (PRA) was also increased in hypertensives. Moreover, urinary kallikrein was increased in hypertensive patients with high PRA (PRA≧mean+1SEM in normotensives; n=25) as compared to patients with normal PRA (PRAkallikrein (r=0.478, p<0.05), as in normotensives (r=0.451, p<0.02). But, no correlation was found in patients with high PRA. Therefore, the results of the present study do not confirm the hypothesis that the deficiency of the kallikrein-kinin system is the primary cause of hypertension. In hypertensives with high PRA, there may be abnormality of the interaction between the renin-angiotensin-aldosterone system and the kallikrein-k...