Splanchnic and renal extraction of circulating hyaluronan in patients with alcoholic liver disease

Splanchnic and renal extraction of hyaluronan was determined in patients with alcoholic cirrhosis (n = 9), non-cirrhotic alcoholic liver disease (n = 5), and controls without liver disease (n = 19) in the supine fasting condition. Arterial plasma concentration of hyaluronan was significantly increased in patients with cirrhosis (mean 480 micrograms/l) as compared to non-cirrhotic patients (29 micrograms/l, P less than 0.001) and controls (25 micrograms/l, P less than 0.001), whereas no difference was present between the two last-mentioned groups. In patients with liver disease, circulating hyaluronan was inversely correlated to indocyanine green clearance (r = -0.85, P less than 0.001) and to galactose elimination capacity (r = -0.62, P less than 0.02), but positively correlated to portal pressure (determined as wedged-to-free hepatic vein pressure) (r = 0.92, P less than 0.001). Splanchnic extraction ratio (arterio-hepatic venous extraction ratio) had a mean value of 0.14 in patients with cirrhosis as compared to 0.36 in non-cirrhotic patients (P less than 0.05) and 0.34 in controls (P less than 0.025). Splanchnic hyaluronan extraction was not correlated to liver function tests or portal pressure. In patients with alcoholic liver disease no significant renal hyaluronan extraction was found as compared to an extraction ratio of 0.17 in controls (P less than 0.05). Our results suggest that the increased level of circulating endogenous hyaluronan found in patients with cirrhosis is caused by a combination of increased supply to and decreased extraction from plasma.     

Hepatic and renal extraction of circulating type III procollagen amino-terminal propeptide and hyaluronan in pig

Hepatic and renal clearance of the amino-terminal propeptide of type III procollagen (PIIINP) and of the glycosaminoglycan, hyaluronan (HA) were investigated in a catheterization study of seven healthy anesthetized pigs. Two assays were used, in order to distinguish between the metabolism of different PIIINP-related antigens. One was the PIIINP RIA Kit, which measures the intact propeptide. The other was the PIIINP Fab assay, in which the antibody has an equal affinity to the intact propeptide and to smaller fragments, of which the latter constitutes most of the antigenic activity in serum. Hepatic and gastrointestinal extraction were evaluated from measurements of serum concentrations in the artery, the portal vein and the hepatic vein. We found a significant hepatic extraction of the intact propeptide (extraction ratio 0.14) and of HA (extraction ratio 0.23), but not of smaller PIIINP fragments. No gastrointestinal extraction of any of the tested substances could be demonstrated. Only smaller PIIINP fragments (such as the col 1 fragment) were extracted by the kidneys (the extraction ratio in the PIIINP Fab assay was 0.19). The renal extraction ratio of HA was 0.14. The amounts of PIIINP fragments and of HA extracted by the kidneys were 50- and 3-times the amounts found in urine, respectively, indicating that the col 1 fragment and HA are degraded in the kidneys in addition to urinary excretion. Our results suggest a dynamic turnover of connective tissue-related components with a fast catabolism of circulating components in liver and kidneys.     

Independent and additional prognostic value of aminoterminal propeptide of type III procollagen circulating levels in patients with chronic heart failure

BACKGROUND: In chronic heart failure (CHF), changes in the extracellular space contribute to cardiac dysfunction. We aimed to determine whether aminoterminal-propeptide of type III procollagen (PIIINP), a marker of extracellular matrix turnover, might provide prognostic information in CHF patients. METHODS AND RESULTS: A total of 101 consecutive CHF patients (mean age 61.7 +/- 8.7 years, 88% males) were followed up between 1999 and 2001. The combined endpoint of the study was death and hospitalization for heart failure. During follow-up there were 15 deaths and 11 hospitalizations for worsening heart failure. At the survival analysis, age (P = .02), New York Heart Association class (P = .014), s-creatinine (P = .014), plasma-PIIINP (p-PIIINP) levels (P = .005), left ventricular ejection fraction (LVEF) (P = .0002), and a restrictive mitral filling pattern (P = .0003) predicted event-free survival. At the multivariate analysis, p-PIIINP levels predicted outcome independently of other clinical variables, hormones, and echocardiographic and exercise testing variables (P < .05 in all models). In patients with LVEF <31%, the presence of p-PIIINP >4.7 microg/L levels was significantly associated with a higher risk of death and hospitalization as compared with the other patients (event-free survival rate at 12 months: 45% versus 95%; at 24 months: 27% versus 88%; at 36 months: 18% versus 85%, P < .0001). CONCLUSIONS: In patients with CHF, PIIINP levels predict outcome independently of clinical status, hemodynamics and hormonal activation. PIIINP levels provide additional prognostic information to that of left ventricular function alone, suggesting that it may reflect more than cardiac extracellular matrix turnover.     

Aminoterminal propeptide of type III procollagen in serum in alcoholic liver disease

An assay of serum antigens related to the aminoterminal propeptide of type III procollagen has been suggested for monitoring fibrotic processes in the liver. These antigens were measured here in 61 alcoholics who were divided into four groups on the basis of liver histology: normal light microscopy, fatty liver, alcoholic cirrhosis with hepatitis, and inactive cirrhosis. All the subjects having alcoholic hepatitis with cirrhosis had elevated values in the assay, whereas some of those with either fatty liver or inactive cirrhosis still had normal values. It was, therefore, not possible on the basis of this method alone to distinguish fatty liver from cirrhosis or alcoholic hepatitis, although very high values were suggestive of alcoholic hepatitis. In a follow-up study, the aminopropeptide value decreased slowly during recovery from alcoholic hepatitis and increased rapidly after a new drinking bout. The antigens detected by the assay are heterogeneous in human serum. The proportions of the three main peptide forms varied during recovery from alcoholic hepatitis, the authentic propeptide being the main one at the acute stage, but almost disappearing later. The usefulness of the assay could probably be improved if distinct assays were available for the different antigen forms.     

Serum concentrations of aminoterminal propeptide of type III procollagen and propeptide of human type I procollagen in systemic lupus erythematosus

The purpose of this study was to assess the association between the serum levels of aminoterminal propeptide of type III procollagen (PIIINP) and carboxyterminal propeptide of type I procollagen (PICP) with disease activity and damage in systemic lupus erythematosus (SLE). Thirty-three patients with SLE were compared with 31 controls. The assessment in SLE included disease activity indices (SLEDAI, MEX-SLEDAI) and damage index (SLICC/ACR). PIIINP and PICP were measured by radioimmunoassay. Compared with controls, mean levels of PIIINP were higher in SLE (2.9±1.8 vs. 1.8±1.2, P=0.006). PICP was also increased in SLE versus controls (163±94 vs. 102±62, P=0.007). PIIINP was correlated with SLICC/ACR (r=0.33, P=0.048). No correlation was observed between PICP and PIIINP with other clinical or therapeutic variables. These preliminary data suggests a role of PIIINP as a marker for chronic damage. Follow-up studies are required to evaluate its utility in predicting future damage.     

Hepatic extraction of the aminoterminal propeptide of type III procollagen before and after bile duct ligation in pigs

The aminoterminal propeptide of type III procollagen is extracted from the circulation by the liver, and PIIINP is found in bile. This study was performed in order to investigate whether biliary excretion contributes substantially to the hepatic extraction of circulating PIIINP. Hepatic extraction before and during a 4-h period after ligation of the common bile duct was assessed from serum PIIINP concentrations in a systemic artery, the portal vein and a hepatic vein of seven healthy anaesthetized pigs. Seven sham-operated anaesthetized pigs served as controls. Ligation of the bile duct did not cause a decrease in the hepatic extraction ratio of circulating PIIINP. The PIIINP serum levels of the cholestatic pigs and of the controls were similar throughout the investigation period. The PIIINP concentrations in bile were only 10% of the corresponding serum values. Gel filtration of sera showed that the lower PIIINP concentration in the hepatic vein, as compared to the artery and the portal vein was due to a selective decrease in the concentration of the intact propeptide. The study shows that biliary excretion does not contribute significantly to the hepatic extraction of circulating PIIINP in the normal liver. Furthermore, the hepatic extraction of circulating PIIINP preferentially affects the intact propeptide, rather than the somewhat larger PIIINP related molecule in serum.     

Is the aminoterminal propeptide of type III procollagen degraded in the liver? A study of type III procollagen peptide in serum during liver transplantation in pigs

The aminoterminal propeptide of type III collagen was monitored in serum during liver transplantation in nine pigs. The aim was to investigate whether removal of the liver causes any changes in the serum concentration of the propeptide. Another connective tissue component, hyaluronan, a glycosaminoglycan known to be degraded in the liver endothelial cells, was also measured. Removal of the liver caused a significant increase in the concentration of the intact propeptide as well as of hyaluronan. Gel filtration confirmed the increase in the amount of intact propeptide. However, another large propeptide-related antigen, eluted near the void volume, appeared in the antigen profile during the anhepatic phase. This peak probably represents the propeptide still attached to the collagen molecule (pN collagen). The findings indicate that the liver is involved in the degradation of the propeptide and of larger propeptide-holding proteins.     

Type III aminoterminal propeptide of procollagen in some haematological malignancies

Marrow fibrosis is involved in some haematological malignancies. Either because of sampling errors, variations of focal distribution of fibrosis or the discomfort for patients of bone biopsies, conventional histology appears to be unsuitable for the follow-up of myelofibrosis. During collagen synthesis by marrow fibroblasts, the aminoterminal propeptide is removed from procollagen III and released in the serum. Thus, a sensitive radioimmunoassay of type III aminoterminal propeptide of procollagen (PC III) has been tested in myeloproliferative and lymphoproliferative disorders with a marked bone marrow fibrosis. In polycythaemia vera, PC III level was significantly increased as compared to controls and was related to marrow fibrosis of grade I. The more increased PC III values were observed in spent polycythaemia cases initially treated by phlebotomy alone. Follow-up showed a transformation into myeloid metaplasia. In contrast, PC III remained stable in patients treated with radiophosphorus 32P or hydroxyurea who did not transform. In myeloid metaplasia, results of PC III were significantly higher than in controls or polycythaemia vera cases. Myelofibrosis of recent onset (less than 2 years) gave higher values than chronic myelofibrosis. Increased PC III values were also emphasized in chronic myelocytic leukaemia, and in a few cases of refractory anaemia with excess of blasts, hairy cell leukaemia and chronic lymphocytic leukaemia.     

Serum hyaluronan and aminoterminal propeptide of type III procollagen in primary biliary cirrhosis: relation to clinical symptoms, liver histopathology and outcome.

Hyaluronan (HA) and aminoterminal propeptide of type III procollagen (PIIINP), two biochemical connective tissue markers, were determined in 76 patients with primary biliary cirrhosis (PBC). The HA and PIIINP concentrations were significantly increased compared with controls (P less than 0.001). Both HA and PIIINP levels correlated significantly with conventional liver-function tests. All patients with stage IV PBC showed increased concentrations of both these variables. However, HA was a better marker with regard to prediction of development of cirrhosis as well as prediction of symptoms. Furthermore, HA also showed a negative correlation with time of survival (P less than 0.05). The present data indicate that HA is a more sensitive marker of liver damage in PBC than PIIINP.     

Serum aminoterminal propeptide of type III procollagen after cardiac transplantation and the effect of rejection

The present study examines serum concentrations of the aminoterminal propeptide of type III procollagen (S-PIIINP), a marker of type III collagen synthesis, after heart transplantation, and assesses changes induced by rejection. Fourteen transplant patients were included with 12 coronary artery bypass patients serving as controls. Mild to moderate rejection was found in 44 biopsies, and severe rejection in 6. Two severe rejection incidents occurred before postoperative day 10, the remainder at postoperative days 23 to 57. S-PIIINP was elevated in transplant patients at postoperative days 1 to 7 (p ≤ 0.01), with return to baseline at postoperative day 60 (p = 0.14, N = 6). S-PIIINP remained unchanged after mild to moderate rejection, but increased 1 to 2 weeks following severe rejection occurring after postoperative day 10. S-PIIINP was elevated in bypass patients from postoperative day 2 throughout the study period of 360 days (p ≤ 0.01). Thus, type III collagen turnover after heart transplant and coronary artery bypass grafting resembles wound healing. Collagen synthesis after severe rejection is reflected by SP-IIINP approximately 2 weeks after transplant. The findings may prove to be significant concerning the prognosis of heart transplant patients.     

Synovial fluid and serum concentrations of aminoterminal propeptide of type III procollagen in healthy volunteers and patients with joint disease.

OBJECTIVES--To analyse synovial fluid and serum concentrations of the amino-propeptide of the type III procollagen (PIIINP) in normal individuals and patients with joint disease, and to explore the relationship between synovial fluid PIIINP concentrations and the rheumatological diagnosis, local inflammation, and joint disease. METHODS--A radioimmunoassay was used to measure the PIIINP concentrations in serum and knee joint synovial fluid from 16 healthy volunteers and patients with osteoarthritis (OA) (n = 40), rheumatoid arthritis (RA) (n = 30), and psoriatic arthritis (PsA) (n = 12). The PIIINP measurements were related to demographic data, synovial fluid leucocyte counts, and radiographic changes at the knee. RESULTS--Serum PIIINP concentrations were greater in each of the disease groups than in control subjects, but there were no differences between the disease groups. Synovial fluid concentrations of PIIINP were much greater than those in serum, indicating local production, and were significantly greater in RA than in other disease groups (p < 0.001). There was only a weak positive correlation between synovial fluid leucocyte counts, some radiographic changes, and synovial fluid PIIINP concentrations. CONCLUSIONS--These data suggest that synovial fluid PIIINP concentrations may reflect local synovial proliferative processes in joint disease, and that they could be of diagnostic and prognostic value in inflammatory arthropathies.     

Biliary excretion of procollagen type III peptide in healthy humans and in patients with alcoholic cirrhosis of the liver

Serum concentrations of procollagen type III peptide are found to be elevated in liver disease and to correlate with fibrosis activity in liver tissue. These elevated serum levels may be due to enhanced synthesis, decreased excretion, or release from deposits of the propeptide in connective tissue. To quantitatively investigate the excretion of procollagen type III peptide, we studied its presence in the bile and urine of 10 healthy controls and 11 patients with alcoholic cirrhosis of the liver. Biliary excretion rates of procollagen propeptide were determined by the duodenal perfusion method. The serum concentrations of procollagen type III peptide were 2.5 +/- 0.5 ng/ml in the healthy controls and 33.6 +/- 6.8 ng/ml in the patients with cirrhosis. Procollagen type III peptide was found in the bile; the healthy controls excreted 0.4 +/- 0.07 nmol/h and the cirrhotics excreted 0.98 +/- 0.27 nmol/h. A fragment of the procollagen propeptide, Col 1, was excreted in urine; the healthy controls excreted 0.25 +/- 0.04 nmol/h, and the cirrhotics excreted 0.11 +/- 0.03 nmol/h. These data demonstrate that the biliary excretion of procollagen type III peptide represents a quantitatively important pathway.     

Serum type III procollagen propeptide levels in acromegalic patients

Serum type III procollagen propeptide (PIIIP) is a reliable index of tissue collagen synthesis. Since in acromegaly there is increased collagen production, we measured serum PIIIP in acromegalic patients before any treatment (basal), during medical treatment with the somatostatin analog SMS 201-995, and after pituitary adenomectomy. In all patients, serum GH and plasma somatomedin-C (SmC) levels were also measured. Basal serum PIIIP levels were significantly (P less than 0.01) higher in acromegalic patients (mean +/- SEM, 22.7 +/- 2.1 ng/ml) than in normal subjects (n = 30; 9.7 +/- 0.5 ng/ml), and they were significantly correlated with plasma SmC values (r = 0.31; P less than 0.05). A significant (P less than 0.01) reduction in PIIIP levels occurred in patients treated with SMS 201-995 or surgery (from 24.3 +/- 2.7 to 12.4 +/- 1 ng/ml) as well as in GH and SmC levels. The maximum percent decrease in serum PIIIP was significantly correlated with those in GH (r = 0.65; P less than 0.01) and SmC (r = 0.60; P less than 0.01). Serum PIIIP levels did not change in those patients in whom neither GH nor SmC were decreased by treatment. In conclusion, serum PIIIP levels are elevated in acromegalic patients, and they decline in parallel with GH and SmC during medical or surgical treatment. Serum PIIIP measurements may be useful in the evaluation of acromegalic patients to gain information on the biological activity of GH and in monitoring the course of the disease.     

Serum levels of aminoterminal type III procollagen peptide in normal subjects and hepatic fibrosis

Serum levels of aminoterminal type III procollagen peptide in normal subjects were determined by radioimmunoassay. The levels of the peptide markedly increase in infants and gradually decrease with age in childhood. The peptide increases again in prepubertal children and then decreases through adulthood. These findings suggest that increased levels of the peptide reflect accelerated collagen synthesis in the human body. Comparison of serum levels of the peptide with the degree of hepatic fibrosis revealed that the peptide increased in parallel with the progress of hepatic fibrosis.     

Aminoterminal propeptide of type III procollagen and hyaluronan in patients with primary biliary cirrhosis: Markers of fibrosis in primary biliary cirrhosis

The aminoterminal propeptide of type III procollagen (PIIINP) and hyaluronan have previously been studied in different liver diseases. The results of these studies are controversial. The aim of the present study was to examine the relationship between PIIINP and hyaluronan levels and the clinical, biochemical and histological features of primary biliary cirrhosis (PBC) and its prognosis. Fifty-five PBC patients were studied at the time of diagnosis of PBC and were followed up for a mean of 58 months. During the follow-up period 21 patients died. In addition, 30 healthy subjects were examined in the present study. Hyaluronan and PIIINP were measured by radioimmunoassay and the levels of both PIIINP and hyaluronan were higher in PBC patients than in healthy volunteers (P< 1.8 times 10^-6 and 1.6 times 10^-9, respectively). Hyaluronan and PIIINP levels were above normal values in 82 and 84% of PBC patients, respectively. There were correlations between PIIINP and hyaluronan and the histological stage of PBC (r=0.44, P< 0.004 and r=0.56, P< 0.00001, respectively). The correlation between PIIINP and hyaluronan was 0.46 (P< 0.0035). In symptomatic patients, both PIIINP and hyaluronan values were higher than in controls (P< 0.002 and P< 0.006, respectively). The levels of PIIINP correlated significantly with bilirubin (r=0.43, P< 0.006), while hyaluronan was correlated with age (r=0.33, P< 0.015), pruritus (r=0.32, P< 0.02), fatigue (r=0.41, P< 0.003), hepatomegaly (r=-0.46, P< 0.0008), the presence of oesophageal varices (r=0.34, P< 0.002), weight loss (r=0.29, P< 0.05), bilirubin (r=0.54, P< 0.0001), albumin (r=-0.30, P< 0.04), extent of fat excretion (r=0.53, P< 0.009) and length of symptomatic period before diagnosis of PBC (r=0.43, P< 0.002). Using Cox's logistic regression analysis, survival was found to be influenced by bilirubin concentration but not by hyaluronan, PIIINP, age, albumin or histological stage. Therefore, hyaluronan is a more sensitive marker for predicting advanced PBC than is PIIINP. However, neither hyaluronan nor PIIINP gave any indication of prognostic outcome.     

Higher levels of serum aminoterminal type III procollagen peptide, and laminin in alcoholic than in nonalcoholic cirrhosis of equal severity.

In vitro models have shown that metabolites of ethanol (acetaldehyde and lactate) stimulate collagen synthesis, thereby, suggesting that they may be important as fibrogenic mediators. The relevance of these findings for fibrogenesis in the human liver in vivo, however, has not as yet been demonstrated. Serum markers for collagen (PIIINP, using radioimmunoassays employing polyclonal antibodies and Fab-fragments (PIIINP-Fab), respectively) and basement membrane (laminin) metabolism were therefore investigated in 25 alcoholic cirrhotics (Pugh-Score: 6.7 +/- 1.9 S.D.) and in 19 comparable nonalcoholic cirrhotics (Pugh-Score: 6.3 +/- 1.5, n.s.) with only slight evidence for inflammation: GOT 28 +/- 22 vs. 24 +/- 21 U/l; GPT 24 +/- 23 vs. 31 +/- 28 U/l; gamma-globulins 24 +/- 8 vs. 22 +/- 5%, respectively (all n.s.). Severity of the disease was assessed by quantitative liver function tests. Levels of PIIINP, PIIINP-Fab and laminin measured by RIA were 21 +/- 19 micrograms/l, 90 +/- 42 micrograms/l and 2.5 +/- 0.8 U/ml in alcoholic cirrhosis and 10 +/- 6 micrograms/l, 61 +/- 10 micrograms/l and 1.9 +/- 0.4 U/ml in nonalcoholic cirrhosis, respectively (all p less than 0.01). Differences on PIIINP and PIIINP-Fab remained significant even after accurate matching for galactose elimination capacity, aminopyrine breath test and hepatic sorbitol clearance. Laminin levels were higher in alcoholic cirrhosis only after matching for the hepatic sorbitol clearance (p less than 0.01). The higher levels of serum markers for collagen and basement membrane metabolism in alcoholic vs. nonalcoholic patients with cirrhosis at equal severity of the disease and with only minimal signs of inflammation may be the clinical reflection of a specific fibrogenic effect of ethanol metabolites.     

Is measurement of type III procollagen amino propeptide useful in primary biliary cirrhosis?

We have examined the value of serum type III procollagen amino propeptide (PIIINP) measurement both in evaluation of disease activity and in estimation of prognosis in primary biliary cirrhosis (PBC). 55 paired sera from 32 PBC patients not receiving treatment known to affect PIIINP levels not with non-hepatic inflammatory conditions were used to estimate serum PIIINP by radioimmunoassay. Significant correlations were found between serum PIIINP and serum albumin (P less than 0.001), bilirubin (P less than 0.002) and aspartate transaminase (P = 0.01). The mean serum PIIINP level rose with advancing histological stage (P less than 0.001). In 18 patients in whom more than 1 serum was assayed (mean follow-up 42 months) PIIINP often fell, particularly in patients with established cirrhosis and advanced disease. The independent prognostic value of PIIINP was examined using Cox's proportional hazards model with three other prognostic co-variables (bilirubin, albumin, patient age). Stepwise regression analysis selected albumin (P less than 0.001) and bilirubin (P = 0.002) as the most important prognostic factors. PIIINP did not give independent prognostic information. We conclude that PIIINP is another marker of disease activity in PBC which confers no benefit over existing conventional measurements in routine management of this disease.     

Serum concentrations of the carboxyterminal cross-linking domain of procollagen type IV (NC1) and the aminoterminal propeptide of procollagen type III (PIIIP) in chronic liver disease

Serum concentrations of both the carboxyterminal cross-linking domain (NC1) of procollagen type IV and the aminoterminal propeptide of procollagen type III (PIIIP) were measured by specific radioimmunoassays in 60 patients with chronic liver disease and 50 healthy controls. Compared with controls (5.3 +/- 1.3 ng/ml, mean +/- S.D.), NC1 concentrations were significantly elevated in patients with chronic active hepatitis (10.2 +/- 2.0 ng/ml) and liver cirrhosis (13.5 +/- 3.0 ng/ml), but not in chronic persistent hepatitis (6.0 +/- 0.9 ng/ml). The concentrations in patients with active liver cirrhosis were significantly higher than those in patients with inactive cirrhosis. Serum concentrations of PIIIP in controls, parients with chronic persistent hepatitis, chronic active hepatitis and cirrhosis were 5.8 (4.3-7.9), 5.3 (3.5-7.9), 17.5 (10.6-28.9), 16.7 (10.4-26.7) ng/ml, respectively (logarithmic mean and range of mean +/- S.D. after retransformation). Patients with liver cirrhosis had significantly higher concentrations of NC1 in serum than those with chronic active hepatitis, but there was no difference in serum PIIIP concentrations between the two groups. These data suggest an alteration of type IV collagen metabolism in chronic liver disease. In liver cirrhosis, the metabolism of collagen IV is apparently different from that of collagen type III; serum NC1 determinations may therefore provide additional information on chronic liver disease, particularly in patients with cirrhosis with a normal level of serum PIIIP. Further follow-up studies as well as investigations related to the basic mechanism of the elevation of these peptides in serum are needed in order to understand their clinical significance fully.     

The serum concentrations of the aminoterminal propeptide of procollagen type III and the hepatic content of mRNA for the alpha 1 chain of procollagen type III in carbon tetrachloride-induced rat liver fibrogenesis.

Serum concentrations of the aminoterminal propeptide of procollagen type III (PIIIP) are elevated in fibrogenic diseases of the liver, but the mechanism of elevation is not fully understood. To investigate the mechanism, we compared serum concentrations of PIIIP with total liver content of mRNA for the pro alpha 1 (III) chain, in rats with carbon tetrachloride (CCl4)-induced liver fibrosis. Adult male rats received CCl4 in mineral oil twice weekly for 8 weeks and were compared with age-matched controls. Serum concentrations of PIIIP were measured by a specific radioimmunoassay; molecular sizes of PIIIP in serum were also determined. Pro alpha 1 (III) mRNA content in the liver was quantitated by RNA slot-blot hybridization and chemical measurement of total hepatic RNA content. Total collagen content of the liver was estimated by hydroxyproline measurement. All CCl4-treated animals had septal fibrosis after 4 weeks, and evidence of cirrhosis (regenerative nodules, ascites) was seen after 7 weeks of treatment. Serum concentrations of PIIIP and pro alpha 1 (III) mRNA content in the liver were correlated well until cirrhosis has established. They increased simultaneously after 3 weeks of treatment, 1 week before any elevation of hepatic hydroxyproline could be detected. After cirrhosis has established, pro alpha 1 (III) mRNA content in the liver decreased markedly, but serum PIIIP levels continued to be elevated. Hepatic hydroxyproline plateaued after 5 weeks. The molecular sizes of serum PIIIP indicate the release of intact native procollagen peptide during the development of cirrhosis. In conclusion, at least in CCl4-induced liver fibrosis in the rats, serum PIIIP levels can be used as a fibrogenic marker for the period progressing to cirrhosis. But the use of the serum PIIIP levels in cirrhosis seems to be limited by factors other than liver fibrogenesis.