Clemente Landriscina
University of Bari
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Featured researches published by Clemente Landriscina.
Toxicology | 2002
Elisabetta Casalino; Giovanna Calzaretti; Cesare Sblano; Clemente Landriscina
Catalase, Mn-superoxide dismutase (MnSOD) and Cu,Zn-superoxide dismutase (CuZnSOD) activities were studied in rat liver and kidney 6-48 h after CdCl(2) intraperitoneal administration or 10-30 days daily oral CdCl(2) intake in drinking water. This approach provided some indications as to the sensitivity of each enzyme to cadmium toxicity. These experiments showed that the formation of thiobarbituric acid reactive substance (TBARS) did not strictly depend on how well the antioxidant enzyme worked. From in vitro experiments it appeared that TBARS removal by vitamin E did not restore the three enzyme activities at all. As for cadmiums inhibitory mechanism on catalase activity, our data, obtained in the pH range 6.0-8.0, are a preliminary indication that the negative effect of this metal is probably due to imidazole residue binding of His-74 which is essential in the decomposition of hydrogen peroxide. Cadmium inhibition of liver mitochondrial MnSOD activity was completely removed by Mn(2+) ions, suggesting that the reducing effect on this enzyme is probably due to the substitution of cadmium for manganese. We also observed the antioxidant capacity of Mn(2+) ions, since they were able to normalize the increased TBARS levels occurring when liver mitochondria were exposed to cadmium. The reduced activity of CuZnSOD does not seem to be due to the replacement of Zn by Cd, nor to the peroxides formed. As this enzyme activity was almost completely recovered after 48 h, we hypothesize that the momentary inhibition is imputable to a cadmium/enzyme interaction. This causes some perturbation in the enzyme topography which is critical for its catalytic activity. The pathological implications linked to antioxidant enzyme disorders induced by cadmium toxicity are discussed.
Lipids | 1984
Francesca Maria Ruggiero; Clemente Landriscina; G.V. Gnoni; E. Quagliariello
Triiodothyronine-induced alteration of the lipid pattern in rat-liver mitochondria and microsomes has been investigated. In mitochondria, a 25% total cholesterol decrease and a 14% phospholipid increase have been detected. In these hyperthyroid rat liver organelles, a strong decrease in the total cholesterol/phospholipid molar ratio occurs. On the contrary, in microsomes from the same animals, a decrease of about 23% has been measured for both total cholesterol and phospholipids; hence, in this fraction, the total cholesterol/phospholipid molar ratio is unaffected by hyperthyroidism. The liver mitochondrial phospholipid composition, unlike the microsomal composition, is altered significantly in hyperthyroid rats; a 7.4% phosphatidylcholine decrease is accompanied by a similar additive percentage increase of both phosphatidylethanolamine and cardiolipin. In regard to total phospholipid fatty acid composition in liver microsomes from hyperthyroid rats, no variation has been observed compared with the control rats, whereas in mitochondria from the same animals, a meaningful linoleic acid decrease with a similar arachidonic acid increase has been found. In addition to fatty acid alteration, the separated mitochondrial phospholipid classes also exhibit some increase in stearic acid. Among phospholipids, cardiolipin changes the most of the esterified fatty acids in hyperthyroid rat liver. In this compound, a strong increase in the percentage of both palmitic and stearic acid and a 32.4% decrease of linoleic acid have been found.
Biochimica et Biophysica Acta | 1968
E. Quagliariello; Clemente Landriscina; P. Coratelli
1. 1. Fatty acid synthesis from [1-14C]acetyl-CoA has been studied in rat-liver mitochondria. The incorporation proceeded linearly for the first 10 min. The activity was greatly increased when the mitochondria were disrupted. The ratio of total radioactivity to radioactivity in carboxyl carbon of the synthesized fatty acids, under all the conditions tested, was always between 1.6:1 and 2.1:1. Both NADPH and NADH were needed for maximum incorporation of [1-14C]acetyl-CoA. 2. 2. Evidence is presented that malonate does not participate to fatty acid synthesis in rat-liver mitochondria. 3. 3. The results indicate that in rat-liver mitochondria fatty acid synthesis proceeds exclusively by chain elongation of endogenous fatty acids via acetyl-CoA. 4. 4. Citrate stimulated [1-14C]acetyl-CoA incorporation into fatty acids by ratliver mitochondria, without affecting the ratio total radioactivity to radioactivity in carboxyl carbon. 5. 5. The enzymes of chain elongation are located in the inner mitochondrial membrane fraction. 6. 6. The labelling pattern of synthesized fatty acids and their incorporation into complex lipids is described.
International Journal of Biochemistry | 1991
P. Morini; Elisabetta Casalino; Cesare Sblano; Clemente Landriscina
1. In liver microsomes from hyperthyroid rats NADPH-dependent lipid peroxidation induces a hydroperoxide formation 56% higher than that in euthyroid ones. 2. The addition of 5 microM Fe2+ (or Fe3+) strongly decreases the hydroperoxide level in favour of that of TBA-reactive substances. Higher iron concentrations (30 microM) have no significant effect. 3. In hepatocytes from hyperthyroid rats CCl4-induced lipid peroxidation produces an amount of TBA-reactive substances four times higher than that in those from euthyroid rats. 4. In the liver of hyperthyroid rats a GSH concentration decrease (by about 35%) is found while the opposite occurs in the blood of the same animals where GSH increases 2.5 times. 5. It is shown that in the liver of hyperthyroid rats, besides higher lipid peroxidation, a more active defense mechanism is operating since both glutathione peroxidase and glutathione reductase specific activities are higher than in euthyroid rats.
Comparative Biochemistry and Physiology C-toxicology & Pharmacology | 2002
Elisabetta Casalino; Giovanna Calzaretti; Cesare Sblano; Vito Landriscina; Mario F. Tecce; Clemente Landriscina
Liver TBARS formation in cadmium-intoxicated rats was completely reduced by administering a low amount of MnCl(2) (2 mg/kg b.w.) 1 h before intoxication. A similar antioxidant effect was first shown by hydroxytyrosol (2-(3,4-dihydroxyphenyl)ethanol, (DPE), a phenolic compound present in olive oil, given twice to rats (9 mg/kg b.w.) after cadmium administration. The antioxidant properties shown in vivo by both Mn(2+) and DPE were also active in vitro when rat liver microsomes were subjected to lipid peroxidation by cadmium or other prooxidant systems. The increase in liver glutathione concentrations occurring in cadmium-intoxicated rats, was also found, for the first time, 24 h after MnCl(2) administration. Unlike cadmium intoxication, which caused a higher formation of both glutathione and TBARS, Mn(2+) induced glutathione synthesis without any TBARS formation. The same situation was also observed when cadmium plus Mn(2+) or cadmium plus DPE was given to rats. Our data show that: (a). both DPE and low Mn(2+) concentrations may have an antioxidant effect in the livers of cadmium-intoxicated rats and (b). Mn(2+), like cadmium, induces liver glutathione synthesis and this effect is probably independent of TBARS formation.
Lipids | 1976
Clemente Landriscina; Francesco M. Megli; E. Quagliariello
Following intraperitoneal administration of 1-14C-linoleic acid or 2-3H-acetate to rats, the specific radioactivities of both liver cardiolipin and other mitochondrial phospholipids after different time intervals were measured. Comparison of the data obtained with those from another stock of rats treated with32P-phosphate or 2-3H-glycerol showed that the fatty acids of cardiolipin, like those of other phospholipids, exhibit an independent turnover with respect to the remaining parts of the molecule. The half-life of acyl moieties of cardiolipin is ca. 20% higher than that of the same components of other mitochondrial phospholipids. Moreover, it appears that, in both cardiolipin and other phospholipids, linoleyl residues turn over faster than nonessential fatty acids. Discussion is made as to whether this characteristic can be related to the role of phospholipids in the functioning of some enzymes bound to the inner mitochondrial membrane.
Toxicology | 2007
Elisabetta Casalino; Giovanna Calzaretti; Matteo Landriscina; Cesare Sblano; Annarita Fabiano; Clemente Landriscina
In rat liver, in addition to their intrinsic transferase activity, alpha-class GSTs have Se-independent glutathione peroxidase activity toward fatty acid hydroperoxides, cumene hydroperoxide and phospholipids hydroperoxides but not toward H(2)O(2.) We have previously shown that hepatic GST activity by these isoenzymes is significantly increased 24h after cadmium or manganese administration (Casalino et al., 2004). Here it is reported that Se-independent glutathione peroxidase activity by alpha-class GSTs is also stimulated in the liver of intoxicated rats. The stimulation is associated with a higher level of alpha-class GST proteins, whose induction is blocked by actinomycin D co-administration. The observed Se-independent glutathione peroxidase activity is due to alpha-class GST isoenzymes, as indicated by the studies with diethyldithiocarbamate which, at any concentration, equally inhibits both GST and Se-independent glutathione peroxidase and is an uncompetitive inhibitor of both enzymes. As for liver Se-GSPx, it is not at all affected under these toxic conditions. For comparison, we have evaluated the status of another important antioxidant enzyme, NAD(P)H:quinone reductase, 24h after cadmium or manganese administration. NQO1 too results strongly stimulated in the liver of the intoxicated rats. In these animals, a higher expression of Nrf2 protein is observed, actively translocated from the cytoplasm to the nucleus. The results with the transcription inhibitor, actinomycin D, and the effects on Nrf2 protein are the first clear indication that acute manganese intoxication, similarly to that of cadmium and other heavy metals, increases both the hepatic level of Nrf2 and its transfer from the cytoplasm to the nucleus where it actively regulates the induction of phase II enzymes.
Biochimica et Biophysica Acta | 1970
Clemente Landriscina; G.V. Gnoni; E. Quagliariello
Abstract 1. 1. Fatty acid synthesis from [1,3- 14 C 2 ]malonyl-CoA has been studied in ratliver microsomes. In the absence of ATP a substancial fatty acid synthesis was observed. The ratio of total radioactivity to radioactivity in carboxyl carbon of the fatty acids synthesized in these conditions was between 7.6:1 and 7.8:1. 2. 2. In the presence of ATP [1,3- 14 C 2 ]malonyl-CoA incorporation was increased. Maximal stimulation was observed at 1 mM ATP. In these conditions the ratio of total radioactivity to radioactivity in carboxyl carbon of the fatty acids synthesized was lowered from 7.9:1 to 3.5:1. By increasing the ATP concentration this ratio was further decreased. 3. 3. The results indicated that in rat-liver microsomes two mechanisms of fatty acid synthesis are present: (a) chain elongation and (b) synthesis de novo . Synthesis de novo is operative maximally in the absence of ATP, whereas chain elongation starts to function in the presence of ATP and becomes the major synthetic pathway when the ATP concentration is increased. 4. 4. Palmityl-CoA inhibited fatty acid synthesis de novo ; simultaneously chain elongation was promoted. 5. 5. Arsenite and AT-ethylmaleimide inhibited both synthesis de novo and chain elongation. The inhibitory concentrations of these compounds were different for the two mechanisms. Chain elongation was completely inhibited at a concentration of arsenite or N -ethylmaleimide 8–10 times higher than that which completely inhibited synthesis de novo . 6. 6. In the absence of ATP, palmitate was the predominant fatty acid synthesized by rat-liver microsomes, whereas in the presence of ATP, stearate, oleate and longer chain fatty acids were synthesized.
Biochemical Medicine | 1980
G.V. Gnoni; Clemente Landriscina; E. Quagliariello
Abstract Fatty acid and cholesterol syntheses are greatly increased in hyperthyroid rat hepatocytes. The incorporation of acetate-2-14C, mevalonate-2-14C, or tritiated water into cholesterol is 35–42% higher than that in normal cells. An interesting finding indicates that the simultaneous administration of cycloheximide and triiodothyronine to hyperthyroid rats reduces or completely abolishes the stimulation induced by the thyroid hormone. Our interpretation is that a larger amount of enzymes catalyzing cholesterol synthesis, initiating from either acetate or mevalonate, is promoted by the thyroid hormone. A significant reduction in both liver fatty acid plus cholesterol synthesis has also been observed in hypothyroid animals.
Biochimica et Biophysica Acta | 1970
Clemente Landriscina; Sergio Papa; P. Coratelli; L. Mazzarella; E. Quagliariello
Abstract Pigeon-liver mitochondria were fractionated by a modification of the method of Sottocasa et al. 5 . The various fractions obtained were examined by electron microscopy. Control experiments excluded the possibility that the activity of rotenone-insensitive NADH-cytochrome c reductase in the various submitochondrial fractions could be largely contributed by microsomal contamination. The submitochondrial localization of the following enzymes in pigeon liver was studied: pyruvate carboxylase, phosphopyruvate carboxylase, NADP + -isocitrate dehydrogenase, glutamate dehydrogenase, aspartate aminotransferase, NAD + -isocitrate dehydrogenase, the enzymes of β-oxidation, malonyl-CoA decarboxylase and the enzymes of fatty acid synthesis. The results indicated that a group of enzymes, consisting of pyruvate carboxylase, phosphopyruvate carboxylase, NADP + -isocitrate dehydrogenase, aspartate aminotransferase, glutamate dehydrogenase and NAD + -isocitrate dehydrogenase, is localized in a fraction practically free of both the inner and outer membranes. This fraction, in agreement with previous reports, is identified as the mitochondrial matrix. It is suggested that NADP + -isocitrate dehydrogenase and aspartate aminotransferase be used as marker enzymes of the mitochondrial matrix. The enzymes of β-oxidation and those of fatty acid synthesis are localized in the inner membrane of pigeon-liver mitochondria 58.4% of the total activity of the mitochondrial malonyl-CoA decarboxylase was found in the inner membrane and 31.4% in the matrix.