Changes in circulating levels of atrial natriuretic factor (ANF) during orthotopic liver transplantation in humans

Atrial natriuretic factor (ANF) is a 28 amino acid peptide secreted by the atrial cardiocytes. Clearance is via the lung (50%) and the liver (25%). The main stimulus to ANF secretion is atrial distension but vasoconstrictors, sympathetic stimulation, catecolamines and tachycardia are able to enhance its circulating blood levels. ANF blood concentrations were measured during orthotopic liver transplantation in six postnecrotic cirrhotic patients. Significant increases in ANF blood levels occurred at the end of the anhepatic phase (P < or = 0.02 vs baseline) associated with low cardiac filling pressures (P < or = 0.02 vs baseline) and increased systemic vascular resistances (P < or = 0.02 vs preanhepatic phase). Aldosterone blood levels showed a similar behaviour, increasing significantly (P > or = 0.001 vs baseline) at the end of the anhepatic phase. ANF fell after reperfusion of the graft and returned towards baseline values at the end of the procedure. Since most of the total body clearance of ANF is performed by the lungs, its sharp increase at the end of the anhepatic phase could be considered a counterregulatory response to vasoconstricting stimulation and to fluid-sparing mechanisms in the presence of relative hypovolaemia. Its decrease after reperfusion could be related to volume normalization and partly to the enhanced clearance performed by the newly grafted liver.

The role of transplantation in small hepatocellular carcinoma complicating cirrhosis of the liver

Of 176 hepatic transplants performed from 1986 to December 1992, 27 patients had small hepatocellular carcinoma (< or = 5 centimeters) complicating cirrhosis of the liver. All patients were asymptomatic for the hepatic malignancy and the diagnosis was established in each instance preoperatively by means of serial sonographic scans and alpha-fetoprotein levels. Cirrhosis was classified as Child's A in eight instances, as Child's B in 16 and Child C's in three. The cause was alcoholic in three patients, posthepatitic in 21 patients (eight hepatitis B virus [HBV] positive and 13 hepatitis C virus [HCV] positive) and undetermined in three. The in-hospital mortality rate was 11 percent (three of 27). Additionally, five patients died at different intervals after transplantation: only two died of neoplastic recurrence at 12 and 32 months, respectively (7.4 percent rate). Actuarial survival rates were 82 percent at one year and 71 percent at three years, with a mean follow-up period of 32 months (range six to 78 months). Morbidity related to the procedure was a relevant problem: 21 percent of the patients had prompt resumption of normal life while 37 percent required repeated hospitalization and 42 percent required strict control on an outpatient basis. The most frequent problem was HBV or HCV reinfection of the grafted liver, which occurred in 42 percent. Based on this experience, transplantation of the liver has shown an excellent oncologic accuracy for small hepatocellular carcinoma in cirrhosis of the liver, thus representing the most rational surgical procedure for patients with Child's B and Child's C cirrhosis classification. The relevant mortality and morbidity rates, strictly related to this procedure, suggest other options as more appropriate in those with Child A cirrhosis at this time.

Somatomedin C (IGF I) plasma levels after orthotopic liver transplantation (OLT) in end-stage cirrhotic patients

Insulin-like growth factors [IGF I and II or somatomedins (SMS)] are polypeptides chemically and biologically correlated with insulin. The main source of synthetic activity and secretion is the liver, although many other tissues have been demonstrated to synthesize SMS. In the circulation, they are not present in a free form, but are mostly bound to a specific carrier protein independently synthesized in the liver. Hepatic or extrahepatic storage organs have not been demonstrated; the half life of the SMS-binding protein complex is between 3 and 4. Synthesis of SMS is regulated by GH, insulin, thyroxine and nutrition (caloric and protein intake, and nitrogen balance). The role of corticosteroids is still a matter of debate: in patients treated with steroids SMS blood levels have been shown to be within normal limits, while biological activity has been demonstrated to be significantly reduced by SMS inhibitors, probably induced by corticosteroid therapy. The biological properties of SMS are related to their structural homology with insulin, and can be summarized as follows: A. Insulin-like activity (glucose oxidation, lipogenesis, glycogen synthesis, inhibition of lipolysis and glycogenolysis); B. Sulphation activity (incorporation of sulphate and leucine into glycosaminglycans of the cartilage); C. Stimulation of fibroblast multiplication; D. Amplification of other hormone activities (GH); E. Complementary anabolic activity with insulin. Low levels of SMS have been demonstrated in hypopituitarism (secondary) or in other diseases independent of GH reduced secretion (primary) such as malnutrition, malabsorption, acute or chronic liver failure and uraemia. Negative nitrogen balance, hypocaloric and/or low protein diets are usually correlated with low levels of SMS. Recently, Schalch et al. reported on the role of orthotopic liver transplantation (OLT) in normalizing SMS blood levels in a group of end-stage liver diseased patients. This preliminary paper deals with changes in IGF-I plasma levels (somatomedin C) in a group of patients affected by end-stage liver cirrhosis before and after OLT.