Relative and combined effects of selenium, protein deficiency and ethanol on hepatocyte ballooning and liver steatosis.

Oxidative damage plays a key role in alcohol-mediated liver alterations. Selenium, a potent antioxidant, is decreased in alcoholics. This study was conducted to analyse if the supplementation with selenium may alter liver changes in a murine model fed ethanol and/or a 2 % protein-containing diet, following the Lieber-DeCarli design. Adult male Sprague Dawley rats were divided into eight groups which received the Lieber-DeCarli control diet; an isocaloric, 36 % ethanol-containing diet; an isocaloric, 2 % protein-containing diet; and an isocaloric diet containing 2 % protein and 36 % ethanol diet; and other similar four groups to which selenomethionine (1 mg/kg body weight) was added. After sacrifice (5 weeks later), liver fat amount and hepatocyte areas of pericentral and periportal cells were measured, and liver and serum selenium, activity of liver glutathione peroxidase (GPX), and liver malondialdehyde were determined. Ethanol-fed rats showed increased hepatocyte areas and fat accumulation especially when ethanol was added to a 2 % protein diet. Selenium caused a decrease in hepatocyte ballooning and liver fat amount, but an increase in GPX activity, and a marked increase in serum and liver selenium. The present study demonstrates that selenium, added to the diet of rats in the form of seleniomethionine, prevents the appearance of early signs of ethanol-mediated liver injury under the conditions of the Lieber-DeCarli experimental design.

TH-1 and TH-2 cytokines in stable chronic alcoholics.

UNLABELLED: In alcoholics, the activation of Kupffer cells by gram negative bacteriae leads to an inflammatory response and cytokine secretion, which in turn activate T-lymphocytes. Possibly, Th-1 lymphocytes are activated first, followed by a Th-2 response. Th-2 cytokines, especially interleukin (IL)-13 (scarcely studied in alcoholics), may be involved in the progression to chronic stages. AIMS: The aim of the study was to analyze the relationship of Th-1 and Th-2 cytokines with liver function, alcohol consumption, nutritional status and survival. METHODS: Serum Th-1 [interferon-γ (IFN-γ)] and Th-2 cytokines (IL-4, IL-13), IL-10, IL-6 and tumor necrosis factor (TNF-α), were determined for 18 controls and 47 stable alcoholics with variable liver function impairment, who were followed-up during a median time of 90 months, a period during which 14 patients died. RESULTS: IL-4 was lower among patients; no differences were observed regarding IL-6, but the remaining ILs were higher among alcoholics. IL-10 and IL-13 were even higher in cirrhotics (Z = 2.88, P = 0.004, and Z = 2.09, P = 0.037, respectively). A significant, direct, correlation was observed between IL-13 and IL-10 (ρ = 0.49, P = 0.001), and non-significant, inverse ones were observed between IFN-γ and IL-13 (ρ = -0.23), IL-4 (ρ = -0.14) and IL-10 (ρ = -0.09). IL-13 and IL-10 were inversely related with liver function and, directly with immunoglobulin A levels, but not with survival. CONCLUSION: Serum IFN-γ values were increased in alcoholics, who also showed raised IL-13 and IL-10, but lower IL-4 levels. Given the immunomodulatory roles of IL-10 and IL-13, this increase may be interpreted as a compensatory rise of anti-inflammatory cytokines. We failed to find any relation with mortality.

Alcoholic myopathy: vitamin D deficiency is related to muscle fibre atrophy in a murine model.

AIMS: Chronic myopathy has been described in alcoholics, characterized by atrophy of type II fibres, and vitamin D deficiency. Low serum vitamin D levels are frequent in alcoholics. The possibility exists that serum vitamin D levels are related to muscle changes in a murine experimental model. METHODS: Histological analysis of the right gastrocnemius muscle was performed in four groups of adult Sprague-Dawley rats, sacrificed after 5 weeks of treatment following the Lieber-DeCarli model. We studied the association between muscle histological changes and the activity of glutathione peroxidase (GPX), superoxide dismutase (SOD) and lipid peroxidation products (malondialdehyde); parathyroid hormone (PTH), insulin-like growth factor 1 (IGF-1), free testosterone, 1,25 dihydroxyvitamin D3 (vitamin D) and corticosterone; and serum calcium and magnesium. RESULTS: Alcoholic animals showed type IIa and IIb fibre atrophy, especially the low-protein-fed ones, an effect dependent on protein deficiency. A significant relationship was observed between serum vitamin D levels and IIa fibre area (rho = 0.56, P = 0.002), and also, as a trend, between vitamin D and type IIb fibre area (rho = 0.39, p = 0.053); between vitamin D and muscle GPX (rho = 0.40, P = 0.025) and SOD activities (rho = 0.43, P = 0.012). Muscle GPX activity was significantly related with type I fibre area (rho = 0.49, P = 0.01) and muscle SOD, with type IIa fibre area (rho = 0.38, P = 0.045). Serum testosterone was also related with type IIa fibre area (rho = 0.61, P < 0.001). No relation was observed between serum PTH, corticosterone, or IGF-1 and fibre area PTH and antioxidant systems. Multiple regression analysis disclosed that the only parameter independently related with type IIa fibre area was serum vitamin D. CONCLUSION: Low vitamin D levels are related to muscle fibre atrophy, and altered levels of muscle antioxidant enzymes could play a role in alcoholic myopathy.

Effect of zinc supplementation on ethanol-mediated bone alterations.

Ethanol consumption leads to bone alterations, mainly osteoporosis. Ethanol itself may directly alter bone synthesis, but other factors, such as accompanying protein malnutrition--frequently observed in alcoholics, chronic alcoholic myopathy with muscle atrophy, alcohol induced hypogonadism or hypercortisolism, or liver damage, may all contribute to altered bone metabolism. Some data suggest that zinc may exert beneficial effects on bone growth. Based on these facts, we analyzed the relative and combined effects of ethanol, protein malnutrition and treatment with zinc, 227 mg/l in the form of zinc sulphate, on bone histology, biochemical markers of bone formation (osteocalcin) and resorption (urinary hydroxyproline excretion), and hormones involved in bone homeostasis (insulin growth factor 1 (IGF-1), vitamin D, parathormone (PTH), free testosterone and corticosterone), as well as the association between these parameters and muscle fiber area and liver fibrosis, in eight groups of adult Sprague Dawley rats fed following the Lieber de Carli model during 5 weeks. Ethanol showed an independent effect on TBV (F=14.5, p<0.001), causing it to decrease, whereas a low protein diet caused a reduction in osteoid area (F=8.9, p<0.001). Treatment with zinc increased osteoid area (F=11.2, p<0.001) and serum vitamin D levels (F=3.74, p=0.057). Both ethanol (F=45, p<0.001) and low protein diet (F=46.8, p<0.01) decreased serum osteocalcin levels. Ethanol was the only factor independently related with serum IGF-1 (F=130.24, p<0.001), and also showed a synergistic interaction with protein deficiency (p=0.027). In contrast, no change was observed in hydroxyproline excretion and serum PTH levels. No correlation was found between TBM and muscle atrophy, liver fibrosis, corticosterone, or free testosterone levels, but a significant relationship was observed between type II-b muscle fiber area and osteoid area (rho=0.34, p<0.01). Osteoporosis is, therefore, present in alcohol treated rats. Both alcohol and protein deficiency lead to reduced bone formation. Muscle atrophy is related to osteoid area, suggesting a role for chronic alcoholic myopathy in decreased bone mass. Treatment with zinc increases osteoid area, but has no effect on TBV.

Alcoholic myopathy: lack of effect of zinc supplementation.

A chronic form of myopathy has been described in alcoholics, characterized by atrophy of type II fibers, due both to reduced protein synthesis and increased protein breakdown. Increased production of reactive oxygen species could probably play a role in increased protein breakdown. In addition, treatment with zinc might be beneficial, since it acts as a cofactor of several enzymes involved in the synthesis of proteins and antioxidants as copper-zinc-superoxidedismutase (SOD) and selenium dependent glutathione peroxidase (GPX). Based on these facts, we analyze the relative and combined effects of ethanol, protein malnutrition and treatment with zinc, 227 mg/l in form of zinc sulphate, on muscle changes in 8 groups of adult Sprague-Dawley rats fed following the Lieber-de Carli model during 5 weeks. We also study the association between muscle histological changes and the activity of GPX, SOD and lipid peroxidation products (MDA), with hormones such as IGF-1, and with trace elements involved in antioxidant systems and/or in lipid peroxidation, such as selenium, copper, zinc, and iron. We found type IIa and IIb fiber atrophy in the alcoholic animals, especially in the low-protein fed ones. This effect was mainly due to protein deficiency. Zinc played no role at all. Muscle iron increased in ethanol, low protein fed rats, either with or without zinc, and was directly related with muscle MDA levels, which in turn were related with muscle atrophy, as was also found for serum IGF-1 levels. Ethanol was the main responsible for all these changes, although protein undernutrition also played an independent role in MDA levels. A positive interaction between ethanol and protein deficiency on serum IGF-1 was also detected. These results suggest that both protein deficiency and ethanol contribute to muscle atrophy observed in alcoholized rats; this atrophy is associated with increased lipid peroxidation and muscle iron overload. Treatment with zinc sulphate confers no benefit.

Combined effects of steroids, ethanol and protein deficiency on tissue content and urinary and faecal excretion of zinc, copper and iron.

This study was performed in order to determine the relative and combined effects of ethanol, a low protein diet and steroid treatment on bone, muscle, liver, and urinary and faecal excretion of zinc, copper and iron in 64 rats divided into eight groups treated following the Lieber-DeCarli liquid diet technique, with and without dexamethasone, 1 mg/l. Steroids showed a lack of effect on liver zinc, but enhanced ethanol- and low protein-mediated liver iron overload when both factors were combined. Steroids also increased muscle copper, iron and zinc, and bone copper, especially in the low protein, ethanol-fed rats.

Relative and combined effects of ethanol and protein deficiency on some hair trace elements: lack of relationship with body stores.

This study was performed in order to analyze the relative and combined effects of ethanol and protein deficiency on hair copper, zinc, manganese, and iron content in four groups of seven animals each which were pair-fed during 8 wk with (1) a nutritionally adequate diet, (2) a 36% (as energy) ethanol-containing isocaloric diet, (3) a 2% protein, isocaloric diet, and (4) a 36% ethanol, 2% protein isocaloric diet, respectively, following the Lieber-DeCarli model, and to analyze the relationship between hair copper, zinc, manganese, and iron content, and the liver and muscle content of these elements. Although there was a trend to higher levels of all the elements analyzed in the the hair of the low-protein fed animals, differences were statistically significant regarding copper and manganese, effects being solely attributable to the low protein diet, not to ethanol. Moreover, hair copper was significantly, inversely related with final weight and weight loss. There were significant relationship between liver zinc and muscle zinc (r = 0.57, p = 0.002), but not between liver or muscle zinc and hair zinc; no correlations were observed between muscle copper and hair copper, nor between liver manganese and hair manganese. An inverse, statistically significant correlation was observed between liver copper and hair copper (r = -0.39, p < 0.05).