1. Previous studies have documented activation of
protease enzymes, such as the
plasma kallikrein-
kinin system, in
hepatic cirrhosis. Increased plasma
kinin generation could contribute to pathological systemic vasodilatation in
cirrhosis, and reduced systemic vascular resistance has been suggested as a trigger to renal
sodium retention in this disease. We investigated the effect of
aprotinin, a
protease inhibitor which binds to
plasma kallikrein, on systemic haemodynamics and renal function in patients with
hepatic cirrhosis and
ascites. 2.
Aprotinin was infused intravenously in high dosage (2 x 10(6)
kallikrein inhibitory units loading, 1 x 10(6)
kallikrein inhibitory units/h). 3. Of 13 patients, 10 had a low systemic vascular resistance (< 1200 dyn s cm-5) at baseline. In this group, eight showed an increase in systemic vascular resistance during
aprotinin infusion. Overall, the increase in systemic vascular resistance was significant, and there was a small but significant increase in mean arterial pressure. In all patients, there were increases in renal plasma flow, glomerular filtration rate, and absolute and fractional urinary
sodium excretion during
aprotinin infusion. 4. Plasma
renin activity, plasma
angiotensin II and plasma
aldosterone fell significantly during
aprotinin infusion. Plasma
prekallikrein, plasma
noradrenaline and plasma
atrial natriuretic peptide did not change. Plasma
aprotinin concentration was 209 +/- 11
kallikrein inhibitory units/ml at the end of the infusion. 5. Before and during the infusion, there was a significant negative correlation between systematic vascular resistance and plasma
renin activity. There was a positive correlation between the change in systemic vascular resistance and the change in renal plasma flow during
aprotinin infusion.(ABSTRACT TRUNCATED AT 250 WORDS)