The Kallikrein-Kinin System in Essential Hypertension

Abstract

The kallikrein-kinin system is a potent vasodilator system with components in plasma and in exocrine glands, including the kidney. Kinins function as local hormones and exert effects on blood vessels and on water and electrolyte balance. The most frequently studied component of this system, urinary kallikrein, has been shown to respond to changes in sodium-retaining steroid activity and in renal blood flow. Urinary kallikrein is subnormal in patients with either essential or renovascular hypertension and supranormal in patients with primary aldosteronism or Bartter's Syndrome. The changes in the kallikrein-kinin system appear to be secondary to changes in blood pressure or in other vasoactive systems: i.e., kinins appear to attenuate the vasoconstrictor effects of angiotensin and stimulate the vasodilator actions of the prostaglandins. The kallikrein-kinin system is altered in hypertension, however, its role in this disease remains unclear.