Urinary kallikrein excretion in congestive heart failure

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

Background

Human 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.

Objective

To evaluate hK1-specific amidase activity in the urine of CAD patients

Methods

Sixty-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.

Results

Urinary 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.

Conclusion

CAD patients had low levels of urinary hK1-specific amidase activity, suggesting that renal KKS activity may be reduced in patients with this disease.

The Amidase Activity of Human Tissue Kallikrein Is Significantly Lower in the Urine of Patients With Systolic Heart Failure

BACKGROUND

Heart failure (HF) is a clinical syndrome that activates several neurohumoral systems. There is little information on the participation of renal kallikrein-kinin system (KKS) in HF. Kallikreins are key enzymes in this system. Thus it was decided to evaluate the role of renal human tissue kallikrein (hK1) in HF patients and, indirectly, to evaluate the role of renal KKS in this disease.

METHODS AND RESULTS

Twenty-eight systolic HF patients, > or =18 years, in New York Heart Association's functional classes II-IV, with left ventricular ejection fraction (LVEF) < or =40%, not receiving angiotensin-converting enzyme inhibitors were selected. Twenty-eight healthy individuals, paired according to gender, ethnics and age, were used as controls. Early-morning midstream urine from every subject was used. hK1 amidase activity was estimated with D-Val-Leu-Arg-Nan substrate. Creatinine was determined by Jaffe's method. hK1 amidase activity was expressed in muM.min(-1).mL(-1) urine and in muM.min(-1).mg(-1) creatinine to correct for differences in urine flow rate. hK1 amidase activities were significantly lower in the urine of HF patients.

CONCLUSION

Because the hK1 amidase activity is significantly lower in the urine of systolic HF patients, it can be supposed that the activity of renal KKS may be suppressed in this disease.