Epithelioid hemangioendothelioma, multiple focal nodular hyperplasias, and cavernous hemangiomas of the liver.

Malignant vascular neoplasms of the liver are uncommon. We report the case of a young woman who developed an epithelioid hemangioendothelioma of the liver associated with multiple focal nodular hyperplasias and hepatic cavernous hemangiomas. Such an unusual association is probably not fortuitous and could support the theory that focal nodular hyperplasia is a reaction to an abnormal vascular supply rather than a true neoplasm.

Acute hepatitis caused by alverine associated with anti-lamin A and C autoantibodies.

We report the case of a 67-year-old woman in whom onset and regression of acute hepatitis were closely related to the time of administration and withdrawal of the smooth muscle relaxant alverine. Antinuclear antibodies were positive, and their titer followed the course of hepatitis. They presented a smooth rim-like nuclear immunofluorescence staining pattern. Immunoblot assay showed that they were directed against lamin A and lamin C. This suggests that alverine should be added to the list of drugs known to produce acute hepatitis, and that drug-induced liver injury is a possible cause of antinuclear antibodies specific for lamin A and lamin C.

Effect of acid-base balance on biliary bicarbonate secretion in the isolated perfused guinea pig liver.

Secretin-induced choleresis is of ductal origin and involves bicarbonate transport. Its mechanism is unknown. To determine the relative effects of systemic pH, PCO2, and bicarbonate concentration on secretin-stimulated bicarbonate transport, states of acute metabolic and respiratory acidosis or alkalosis were created in isolated perfused guinea pig livers with or without secretin infusion. During spontaneous secretion conditions, biliary bicarbonate secretion was not correlated with perfusate pH (7.19-7.62) or perfusate PCO2 (23.9-59.7) but was significantly correlated with perfusate bicarbonate concentration (17.5-37.9 mM). Under secretion infusion (25 mU/min), bile flow and biliary bicarbonate concentration increased significantly (109 and 51%, respectively). Biliary bicarbonate secretion was not correlated with perfusate pH (7.19-7.60) but was significantly correlated both with perfusate bicarbonate concentration (14.6-36.8 mM) and PCO2 (25.8-54.3 mmHg). Spontaneous and secretin-induced bile flow were correlated with biliary bicarbonate concentration. The correlation between biliary bicarbonate secretion and PCO2 during secretin-induced choleresis supports the hypothesis that secretin-induced biliary bicarbonate secretion could, at least in part, involve a transport of H+ (or OH-) rather than HCO3- itself and that intracellular pH could play a role in the regulation of this secretion. Amiloride (5 X 10(-4) M) did not influence secretin-induced biliary bicarbonate secretion. This result suggests that the Na(+)-H+ exchange is not involved in bicarbonate secretion by ductular cells.

Clotiazepam-induced acute hepatitis.

We report the case of a patient who developed acute hepatitis with extensive hepatocellular necrosis, 7 months after the onset of administration of clotiazepam, a thienodiazepine derivative. Clotiazepam withdrawal was followed by prompt recovery. The administration of several benzodiazepines, chemically related to clotiazepam, did not interfere with recovery and did not induce any relapse of hepatitis. This observation shows that clotiazepam can induce acute hepatitis and suggests that there is no cross hepatotoxicity between clotiazepam and several benzodiazepines.

Permeability of the rat biliary tree to ursodeoxycholic acid.

The permeability of the biliary epithelium to [14C]ursodeoxycholic acid (UDCA), a hypercholeretic bile acid, was compared to that of the 14C-labeled nonhypercholeretic bile acids cholic acid (CA), taurocholic acid (TCA), and tauroursodeoxycholic acid (TUDCA) by means of anterograde intrabiliary infusions and retrograde intrabiliary injections in the anesthetized rat. Anterograde intrabiliary infusions were performed by perfusing an isolated segment of common bile duct in vivo. After anterograde intrabiliary infusions, the fraction of unrecovered UDCA (that had presumably been absorbed from the biliary lumen) was 11.03 +/- 1.03 (SE)% (n = 6) of the administered dose. It was significantly higher than that of TUDCA (1.25 +/- 0.27%; n = 5; P less than 0.01), CA (2.62 +/- 0.43%; n = 4; P less than 0.01), and TCA (2.57 +/- 0.79%; n = 6; P less than 0.01). In separate experiments, bile was collected from the common bile duct and from the left hepatic duct. UDCA recovered from the left hepatic duct was found in the conjugated form, indicating that, after absorption in the common bile duct, it had been conjugated by the hepatocyte and secreted into bile. After retrograde intrabiliary injections of UDCA and CA, the cumulative percentages of recovered radioactivity were not significantly different (84.50 +/- 2.65 and 87.33 +/- 1.80%, respectively); however, peak recovery of UDCA was significantly delayed compared with that of CA. Moreover, UDCA was recovered mostly in the conjugated form, while CA was recovered mostly in the unconjugated form. These results suggest that, in the rat, UDCA is significantly more absorbed by the biliary tree than CA, TUDCA, and TCA. They support the hypothesis that UDCA undergoes a cholehepatic circulation.

Modifications of concanavalin A patterns of alpha 1-acid glycoprotein and alpha 2-HS glycoprotein in alcoholic liver disease.

In order to test whether abnormalities in hepatocytes affect the glycoprotein carbohydrate moiety, crossed immunoaffinoelectrophoresis (CIAE) with Concanavalin A (Con A) was used to study serum alpha 1-acid glycoprotein (alpha 1-AGP) and alpha 2-HS glycoprotein (alpha 2-HS) obtained from alcoholic patients with biopsy-proven liver disease. Cirrhotic patients, placed in groups C1, C2 or C3, according to Pugh's classification, were compared to healthy donors (N) and to steatosic non-cirrhotic patients (S). Con A CIAE patterns revealed in group N three subpopulations for alpha 2-HS and four for alpha 1-AGP. Two main results emerged from this study: (1) in the alcoholic groups, the proportions of Con A-unreactive subpopulations of both glycoproteins increased. Moreover, group N could be separated from group S and group S from all the cirrhotic groups. (2) There was a good correlation between the relative amounts in Con A-unreactive subpopulations of alpha 1-AGP and alpha 2-HS. The increases observed in Con A-unreactive subpopulations are probably a general phenomenon related to alterations in glycosylation processing during liver cell damage.

Alterations in relative proportions of microheterogenous forms of human alpha 1-acid glycoprotein in liver disease.

To determine whether liver damage correlates with typical changes in alpha 1-acid glycoprotein (alpha 1-AGP) carbohydrate branching, we selected patients with liver disease determined by histological liver findings. The severity of their illness was assessed by a clinical classification depending on the presence singly or together of four clinical complications (jaundice, ascites, hepatic encephalopathy and weight loss). An alpha 1-AGP crossed immunoelectrophoresis with Concanavalin A, an easy-to-perform method, revealed 3 or 4 subpopulations, the areas of which were calculated. A ratio R was determined as the most anodic peak area relative to the other ones. In our experimental conditions a ratio R value exceeding 1 correlated with the presence of one or more clinical complications. These results, evidencing fluctuations in the proportion of the carbohydrate variants of alpha 1-AGP, lead us to propose such a ratio as an index for grading liver damage. The sensitivity of this test was 86% and its specificity was 83%.

Role of H+ transport in ursodeoxycholate-induced biliary HCO-3 secretion in the rat.

Biliary bicarbonate secretion may occur by transport of bicarbonate itself or of H+ (or OH-). To distinguish between these two mechanisms, we have studied the effects of bicarbonate deprivation or substitution by weak acids in the perfusate of isolated rat livers on ursodeoxycholate-induced bicarbonate secretion. Livers were perfused with an erythrocyte-free solution containing either the impermeant buffer Tricine (25 mM) or 25 mM Tricine and 13 mM bicarbonate, acetate, or 5,5-dimethyloxazolidine-2,4-dione (DMO), and ursodeoxycholate was infused. Tauroursodeoxycholate, which does not stimulate bicarbonate secretion, served as a control. During ursodeoxycholate infusion 1) the increase in bile flow, in microliter X min-1 X g liver-1 (+/- SE), was significantly higher in livers perfused with Tricine and bicarbonate (1.29 +/- 0.06), Tricine and acetate (1.46 +/- 0.07), and Tricine and DMO (1.30 +/- 0.04) than in livers perfused with Tricine alone (0.99 +/- 0.04); and 2) biliary bicarbonate, acetate, or DMO concentrations and bile pH were significantly higher than the corresponding perfusate values. In contrast, during tauroursodeoxycholate infusion bile flow was the same whatever the perfusate, and bile pH was lower than pH of the perfusate. Therefore, ursodeoxycholate-induced choleresis and bile alkalinization do not depend on bicarbonate as such (which can be replaced by acetate or DMO). This suggests that ursodeoxycholate-induced biliary bicarbonate secretion is the result of H+ (or OH-) transport rather than transport of bicarbonate itself.

Effect of systemic pH, PCO2 and bicarbonate concentration on biliary bicarbonate secretion in the rat.

The effect of acute metabolic or respiratory acid-base disturbances on biliary bicarbonate secretion was examined in bile fistula rats. Animals were infused with ursodeoxycholate at a rate that stimulates bicarbonate secretion (1 mumole . min-1 X 100 gm-1), in control conditions and during acute acid-base disturbances. Metabolic acidosis or alkalosis were induced by HCl or NaHCO3 infusions, and respiratory acidosis or alkalosis were created respectively by adding CO2 to the inspired gas or by hyperventilation in artificially ventilated animals. Biliary bicarbonate concentration was always higher than plasma bicarbonate concentration. During metabolic disturbances, changing the plasma bicarbonate concentration from 9.2 to 30.2 mM stimulated biliary bicarbonate secretion by 113%. During respiratory disturbances, changing the plasma PCO2 from 25.5 to 59.8 mm Hg also increased biliary bicarbonate secretion by 89%. Biliary bicarbonate output was thus independent of plasma pH. When all animals were considered, bile flow was positively correlated with biliary bicarbonate concentration (r = 0.71, p less than 0.001). Acetazolamide significantly decreased ursodeoxycholate-induced bile flow and bicarbonate secretion by 20 and 22%, respectively. These results support the hypothesis that there is a relationship between ursodeoxycholate-induced bicarbonate secretion and bile flow. They are also consistent with the view that ursodeoxycholate-stimulated biliary bicarbonate secretion in the rat is strongly affected by plasma bicarbonate and PCO2, but not by plasma pH, and involves carbonic anhydrase.

Regulation of renal cytochrome P-450. Effects of two-thirds hepatectomy, cholestasis, biliary cirrhosis and post-necrotic cirrhosis on hepatic and renal microsomal enzymes.

The possibility of a relationship between hepatic and renal cytochrome P-450 contents was assessed in rats with liver disease. In rats killed 3 days after two-thirds hepatectomy (a model for hepatocellular insufficiency), the total microsomal cytochrome P-450 content of the whole liver was decreased by 60% as compared to that in control rats; renal cytochrome P-450 was increased by 30% while the 7-ethoxycoumarin deethylase activity of kidney microsomes was increased by 80%. In rats killed 7 days after bile duct ligation (a model for cholestasis) or 35 days after bile duct ligation (a model for biliary cirrhosis), hepatic cytochrome P-450 was decreased by 60% and 45%, respectively, while renal cytochrome P-450 content was increased by 50% and 150%, respectively. In contrast, in rats killed 15 days after the last dose of carbon tetrachloride, 1.3 ml/kg twice weekly for 3 months (a model for post-necrotic cirrhosis), both hepatic and renal cytochrome P-450 contents remained unchanged. Phenobarbital (80 mg/kg daily for 3 days) was a poor inducer of renal cytochrome P-450 in sham-operated rats but became a potent inducer of renal cytochrome P-450 in rats with two-thirds hepatectomy. We conclude that renal cytochrome P-450 is increased in three models in which hepatic cytochrome P-450 contents are decreased (two-thirds hepatectomy, cholestasis and biliary cirrhosis), but remains unchanged in a model of severe liver pathology, in which hepatic cytochrome P-450 content is not modified (late, post-necrotic cirrhosis). The hypothetical role of endogenous inducer(s) is discussed.

Bicarbonate-stimulated ATPase activity of bovine liver alkaline phosphatase.

A commercial preparation of bovine hepatic alkaline phosphatase was found to have a Mg2+-stimulated ATPase activity. The pH optimum was 8.5, the Km for ATP was 4.2 X 10(-5) M and the Vmax was 88.3 mumol Pi . h-1 . mg-1. HCO3- had a stimulatory effect on Mg2+ -ATPase activity. Other anions had no effect or an inhibitory effect while Na+, K+ and ouabain had no effect. Purification of the commercial preparation by gel filtration and affinity chromatography yielded a fraction with alkaline phosphatase and (Mg2+ + HCO3-)ATPase activities that had been enriched respectively 27-fold and 23-fold; both activities were inhibited by levamisole (93.1% and 93.8%, respectively) and the purified fraction was found to be a single protein on sodium dodecyl sulfate polyacrylamide gel electrophoresis. These results suggest that alkaline phosphatase and (Mg2+ + HCO3-)ATPase may be properties of the same liver protein that might be involved in biliary HCO3- transport and bile secretion.

Effect of acid-base balance and acetazolamide on ursodeoxycholate-induced biliary bicarbonate secretion.

Biliary bicarbonate secretion may play an important role in canalicular bile flow. The aim of this study was to examine the effect of disturbances in acid-base balance on ursodeoxycholate (UDCA)-induced choleresis and bicarbonate secretion. Isolated rat livers were perfused with an erythrocyte-free solution in a recirculating system. In the absence of bile acid infusion, bicarbonate concentration in bile varied in parallel with that in the perfusate (15.6-35.1 mM), irrespective of the perfusate pH (7.26-7.55). Bicarbonate concentration in bile was not significantly different from that in the perfusate. Under UDCA infusion (2 mumol/min), bicarbonate concentration in bile and perfusate was correlated (P less than 0.001). Bicarbonate concentration in bile was always higher than that in the perfusate. Perfusate pH changes (7.25-7.56) induced by changes in perfusate carbon dioxide tension had no significant effect on bicarbonate secretion or bile flow. A significant correlation was found between bile flow and bicarbonate secretion both with and without UDCA. Acetazolamide (1 mM) significantly decreased both UDCA-stimulated bile flow (-27.7%) and bicarbonate concentration (-51.8%). These results suggest that canalicular bicarbonate secretion includes an equilibrative component that is possibly linked to diffusion of plasmatic CO2 or HCO3- and a concentrative transport that is stimulated by UDCA, is independent of plasma pH, and involves carbonic anhydrase.

A new method to measure portal and hepatic blood flow using taurocholate in the rat.

Hepatic artery and portal vein blood flows were assessed separately in anesthetized rats using radiolabeled taurocholate. The ratio of portal vein blood flow to total hepatic blood flow was calculated from measurements of taurocholate concentrations of portal vein, hepatic artery and hepatic vein, and of taurocholate hepatic extraction ratio. Animals were administered [14C]taurocholate intraperitoneally as a label of the taurocholate pool 24 hr before the experiments. In steady-state conditions, serum [14C]taurocholate activities were used as an index of taurocholate relative concentration and the hepatic extraction ratio of taurocholate was estimated using [3H]taurocholate infused into the systemic blood stream. Total hepatic blood flow was estimated by the Fick's principle using indocyanine green. The mean hepatic blood flow was 13.9 ml X min-1 (S.E. 1.9), and the mean ratio of portal blood flow to hepatic blood flow was 72.2% (S.E. 6.7). It is concluded that taurocholate may be used to assess separately portal venous and hepatic arterial blood flow in the rat.

Measurement of serum alpha 1-acid glycoprotein and alpha 1-antitrypsin desialylation in liver disease.

To determine whether the presence of circulating desialylated glycoproteins reflect the existence and/or the severity of liver disease, 73 patients were evaluated with liver biopsies, conventional liver function tests, and the measurement of the degree of desialylation of two glycoproteins alpha 1-acid glycoprotein (alpha 1-AGP) and alpha 1-antitrypsin (alpha 1-AT). A combination of two immunological methods, available as routine laboratory tests, was used for the determination of the desialylation of alpha 1-AGP and alpha 1-AT. The severity of liver disease was assessed by a clinical classification depending upon the presence or absence of four complications (jaundice, ascites, hepatic encephalopathy, and weight loss). The presence of serum desialylated alpha 1-AGP did not allow detection of mild liver disease, but asialo alpha 1-AGP (and to a lesser extent of asialo-alpha 1-(AT) correlated with the severity of liver disease. The sensitivity of desialylated alpha 1-AGP in detection of severe liver disease was 65%, and its specificity was 80%.

Choleretic and diuretic properties of dihydroxydibutyl ether in the rat.

Dihydroxydibutyl ether (DDE) induces a choleresis and a diuresis in the rat. The stimulation of bile flow is immediate and dose-dependent; DDE appears to stimulate bile acid-independent flow of canalicular origin, because erythritol clearance increased in parallel to bile flow and choleresis occurs in the absence of an increased bile acid secretion. Increased bile flow may be accounted for by the osmotic activity of DDE and DDE metabolites excreted into bile, with an average increase in bile flow of 16 microliters/mumol of DDE (or DDE metabolites). Biliary secretion of DDE is limited with a maximal rate (biliary Tm) of 773 nmol.min-1.100 g b.wt.-1. The metabolic products of DDE in bile appear to be its mono- and diglucuronide conjugates inasmuch as DDE can be recovered after beta-glucuronidase incubation. DDE and a DDE glucuronide conjugate are also detected in the urine: there is an apparently linear relation between DDE (and DDE metabolites) excretion rate and increase in urinary flow (3.5 microliters/mumol of DDE or DDE metabolites). It is concluded that DDE stimulates choleresis and diuresis in the rat because the molecule and its glucuronide conjugates are secreted and concentrated in bile and urine.

Propranolol--a medical treatment for portal hypertension?

Continuous, oral administration of propranolol at doses which reduced the heart-rate by 25% produced a sustained decrease in portal venous pressure in cirrhotic patients with portal hypertension. This effect of propranolol might be useful in preventing recurrent bleeding due to ruptured oesophageal varices in patients with portal hypertension.