The circulating level and splanchnic and renal extraction of serum type I procollagen aminoterminal propeptide (PINP) was studied in 20 patients with normal liver function and in 15 patients with alcoholic liver cirrhosis. In patients with alcoholic cirrhosis, the concentration of PINP in the femoral artery blood was significantly higher than in the group of patients with normal liver function (median 145 microg/l, 95% CI 98-195 versus 57 microg/l, 95% CI 42-92, p<0.001). A significant decrease in the concentration of PINP between the femoral artery (median 57 microg/l, 95% CI 42-92) and the hepatic vein (median 45 microg/l, 95% CI 40-70, p<0.001) was found in patients with normal liver function. In this group we also observed a significantly higher concentration of PINP in femoral artery blood (median 60 microg/l, 95% CI 45-87) as compared with that in renal vein (median 50 microg/l, 95% CI 40-65, p<0.001). In contrast, serum-PINP did not differ between arterial and hepatic or venous venous blood in patients with alcoholic cirrhosis. Size-chromatography revealed no significant change in the ratio of the high and low molecular forms of PINP following extraction in liver and kidney. It is concluded that circulating PINP is extracted in the normal liver and kidney, and that the serum concentration of PINP is significantly higher in patients with alcoholic cirrhosis than in patients with normal liver function. Both the hepatic and the renal clearance of PINP are seriously impaired/reduced in patients with alcoholic cirrhosis.