Human Tissue Kallikrein Activity in Angiographically Documented Chronic Stable Coronary Artery Disease

Abstract

BackgroundHuman tissue kallikrein (hK1) is a key enzyme in the kallikrein–kinin system (KKS). hK1-specific amidase activity is reduced in urine samples from hypertensive and heart failure (HF) patients. The pathophysiologic role of hK1 in coronary artery disease (CAD) remains unclear.ObjectiveTo evaluate hK1-specific amidase activity in the urine of CAD patientsMethodsSixty-five individuals (18–75 years) who underwent cardiac catheterism (CATH) were included. Random midstream urine samples were collected immediately before CATH. Patients were classified in two groups according to the presence of coronary lesions: CAD (43 patients) and non-CAD (22 patients). hK1 amidase activity was estimated using the chromogenic substrate D-Val-Leu-Arg-Nan. Creatinine was determined using Jaffé’s method. Urinary hK1-specific amidase activity was expressed as µM/(min · mg creatinine) to correct for differences in urine flow rates.ResultsUrinary hK1-specific amidase activity levels were similar between CAD [0.146 µM/(min ·mg creatinine)] and non-CAD [0.189 µM/(min . mg creatinine)] patients (p = 0.803) and remained similar to values previously reported for hypertensive patients [0.210 µM/(min . mg creatinine)] and HF patients [0.104 µM/(min . mg creatinine)]. CAD severity and hypertension were not observed to significantly affect urinary hK1-specific amidase activity.ConclusionCAD patients had low levels of urinary hK1-specific amidase activity, suggesting that renal KKS activity may be reduced in patients with this disease.

High Level of Serum Tissue Kallikrein Is Associated with Favorable Outcome in Acute Ischemic Stroke Patients

“…TK has been demonstrated to be associated with several diseases, especially cardiovascular disease and stroke. People with hypertension [19], heart failure [20], or coronary artery disease (CAD) [21] were found to have low levels of urinary human TK activity compared with controls. However, another study proposed that higher levels of TK in plasma were associated with the presence of CAD and were a predictor of mild coronary arteriosclerosis [11].…”