[Contribution of glutathione to detoxification in alcoholism. Biochemical-clinical studies]. / L'apporto di glutatione nella detossificazione dell'alcolismo. Indagini biochimico-cliniche.

The effects of reduced glutathione (GSH) administration (1.2 g/day and 2.4 g/day intravenously) on erythrocyte glutathione levels, serum gamma-glutamyl transpeptidase activity (GGTP) and urinary glucaric acid elimination were studied in a population of 24 chronic alcoholics voluntarily admitted to a 30 day detoxification protocol in comparison to a 12 patient control group treated only with chlordiazepoxide (initial dose 75-100 mg/day). Glutathione treatment increases dose-dependently and in a significant way erythrocyte glutathione levels and hastens the recovery of serum GGTP and urinary glucaric acid elimination. The relationship between glutathione, GGTP and glucaric acid is discussed, suggesting the possible role of GSH against the oxidative damage of alcohol.

HBV and HCV infection in i.v. drug addicts; coinfection with HIV.

A group of 122 drug addict patients were studied to evaluate the incidence of HIV, HBV, HCV infections and of laboratory findings of hepatic damage. Our data show that hepatic damage is more frequent in patients affected by HBV-HCV coinfection than those with HBV or HCV infection alone and that HIV positivity supports HBV-HCV coinfection.

Galactose loading tests in patients with hepatocellular carcinoma for the assessment of chemotherapy.

Patients affected by liver cirrhosis with and without hepatocellular carcinoma (HCC) underwent galactose testing for the assessment of both quantitative liver function and effective blood flow. The galactose elimination capacity (GEC), when investigating the former parameter, resulted in being significantly reduced in cirrhotics (29.5%) and in cirrhotics with HCC (42.9%) when compared to controls. The galactose clearance, expressing the effective blood flow through the liver, showed a significant decrease (34.0%) only in the group with superimposed HCC. Our results pointed out a significant impairment of effective hepatic blood flow and an overall reduction of hepatic metabolic activity in the cirrhotics with HCC. These data suggest that lower amounts of chemotherapeutic agents must be given to patients affected by cirrhosis with HCC, especially when dealing with substances mainly metabolized by the liver. On the basis of our results, such a reduction was evaluated to be around 50% of the total dosage.

Chemotherapy of primary and secondary liver cancer: is it useful?

The therapeutic efficacy of three different antiblastic regimens was tested in patients affected by primary or secondary liver cancer. The association of cyclophosphamide and adriamycin gave the best results, despite no partial remission observed with any treatment. As regards the efficacy of antiblastic therapy in this type of tumor, we must conclude that the only detectable effect is a transient improvement of the course of the disease.

Vasoactive factors in the mechanism of renal sodium handling in cirrhotics: the effect of acute plasma expansion.

Twenty cirrhotic patients with ascites, divided into two groups of 10 each, according to their daily urinary sodium excretion (sodium retainers and sodium excretors) and given a diet of 75 mEq of sodium daily, underwent acute plasma volume expansion with 1,000 ml of 10% dextran in saline, infused through a catheter located in the right atrium. Even if a significant increase in sodium excretion was observed in both groups (p less than 0.001 in sodium excretors and p less than 0.05 in sodium retainers), plasma expansion did not reverse sodium retention in sodium retainers. A significant increase in creatinine clearance was found only in sodium retainers (p less than 0.02). Basal plasma renin activity and plasma aldosterone were elevated only in a few patients of both groups. The renin-angiotensin-aldosterone system was highly responsive to plasma expansion. Sodium retainers, who showed an ineffective natriuretic response after expansion, were able to suppress both plasma renin activity and plasma aldosterone in an analogous manner to the sodium-excreting group. This result lends strong support to the concept that the elevated aldosterone level in cirrhosis is not the major determinant of sodium retention. The kallikrein-kinin system was responsive to volume stimulus, since a decrease in kallikrein excretion was noted. It was significant in sodium retainers (p less than 0.05). Plasma PGE1,2 levels were significantly higher in sodium retainers than in controls. This may suggest that there is an activation of the intrarenal prostaglandin system, which could play a protective role against renal ischaemia. After volume expansion, PGE1,2 increased, but not significantly. Octopamine appeared unrelated to sodium excretion and unresponsive to volume stimulus. Endotoxins did not seem to be involved in renal sodium handling. Plasma volume expansion seemed effective in inducing a reduction of vasoconstrictor and sodium-retaining factors, such as the renin-angiotensin-aldosterone system. It is possible to suggest that volume expansion could increase PGE1,2. Plasma volume expansion produced different rates of sodium excretion in the two groups of patients and this suggests that impaired sodium handling in cirrhosis could, to some extent, be independent of effective plasma volume.

Vasoactive factors in decompensated cirrhosis. Effect of acute plasma expansion.

Plasma volume expansion was performed in 16 cirrhotic patients with ascites, 8 with avid sodium retention (sodium retainers) and 8 with normal sodium balance (sodium excretors). No natriuretic response was observed in sodium retainers (daily UNa = 7.1 +/- 1.5 mEq before expansion and 20.8 +/- 7.8 after expansion; p = not significant). After expansion plasma renin activity and plasma aldosterone showed a fall in both groups, whereas urinary kallikrein excretion decreased significantly in sodium retainers (27.1 +/- 9.7 before expansion and 7.8 +/- 6.4 after expansion; p less than 0.05). Baseline PGE were higher than normal in sodium retainers (997.0 +/- 134.3; p less than 0.02 vs. controls) and increased after expansion. Plasma octopamine was always within normal range. These results suggest that: a) reduction of effective plasma volume is not the main factor involved in sodium retention; b) the renin-angiotensin-aldosterone system has only a permissive role; c) prostaglandin system is activated and could have a protective role in maintaining renal function in cirrhotic patients.

Regulation of urinary thromboxane B2 in man: influence of urinary flow rate and tubular transport.

Thromboxane B2 (TxB) is excreted in human urine, but the mechanism of renal excretion and the quantitative relationship of urinary TxB to the active parent compound, thromboxane A2, of renal or extrarenal origin is not established. To determine the effects of vasoactive hormones, uricosuric agents and urinary flow rate on TxB excretion, urinary TxB was measured by radioimmunoassay and mass spectrometry, and renal metabolism of blood TxB was determined by radiochromatography of urine after i.v. [3H]-TxB infusions. Basal TxB was 6.7 +/- 1.1 ng/h during an oral water load, and TxB fell with s.g. antidiuretic hormone (to 3.4 +/- 0.4 ng/h, P less than 0.01) and with fluid restriction (to 2.6 +/- 0.5 ng/hr, P = 0.001) in parallel with urinary volume. Urinary excretion of unmetabolized [3H]-TxB also fell (by 56%) with fluid restriction, implicating altered metabolism rather than synthesis as the mechanism of the urinary flow effect. Angiotensin II infusions slightly reduced both TxB and urine volume, consistent with a flow effect. In contrast, probenecid did not alter urine volume, but increased urinary uric acid (by 244%), TxB (from 5.6 +/- 0.9 to 11.1 +/- 2.9 ng/h) and urinary excretion of blood [3H]-TxB (by 243%) by similar amounts (all P less than 0.05), suggesting that TxB is actively reabsorbed in the proximal tubule, similarly to uric acid. Thus, urinary excretion of TxB of renal and extrarenal origin is regulated by proximal and distal tubule factors.

Systemic hemodynamics and renal function in cirrhotic patients during plasma volume expansion.

Systemic hemodynamic impairment (hepatocirculatory failure) has been suggested as one of the possible factors which may explain the renal hemodynamic alterations found in the late stage of liver cirrhosis, typical of the hepatorenal syndrome. 20 patients, divided into two groups of 10 sodium retainers and 10 sodium excretors, affected by liver cirrhosis with portal hypertension and ascites, were studied. Renal functional parameters (diuresis, urinary and plasma electrolytes, urine to plasma osmolality and creatinine ratios and creatinine clearance) were evaluated before and after acute volume expansion with 1,000 ml of 10% dextran in saline, infused through a catheter located in the right atrium. Hemodynamic tests (cardiac index, systemic vascular resistance, right atrial pressure and capillary wedge pressure) were performed before, during and after expansion. Cardiac index decreased in 6 patients (sodium excretors) after a 500-ml infusion and rose again after 1,000 ml in 5 of them. The remaining 14 patients showed a progressive and significant increase of cardiac index. A strong inverse relationship between cardiac index and systemic vascular resistance was observed (r = -0.87; p less than 0.001). The mean left-ventricular function curve showed a slow response in most sodium excretors and a normal response in the sodium-retaining group, without significant difference between the two groups. Sodium excretion significantly improved after expansion in both groups of patients. No relationship was found between hemodynamic response and renal function. These data show that cardiocirculatory function is normal, even in sodium-retaining cirrhotics.

Functional renal alterations in chronic liver diseases.

83 patients with chronic active hepatitis (CAH), 38 of them with cirrhosis, were studied and compared with 10 control subjects suffering from chronic persistent hepatitis (CPH). Tubular acidosis frequently was found in our cases. Renal plasma flow and glomerular filtration rate were significantly decreased in CAH when compared with CPH. Selective renal arteriography showed evident decrease of arterial flow in the outer cortex. Selective renal scan with 99mTc microspheres of human albumin showed a frequent escape of the tracer from the kidney to the lung. PGE1 and PGE2 levels appeared higher in the renal artery than in the vein and were significantly more elevated in 9 cases with cirrhosis vs. 13 controls. These results suggest the frequent functional impairment of the kidney also in the early stages of CAH, with an increase of PGE levels and an opening of intrarenal shunts.