Oxidase activity of ceruloplasmin and concentrations of copper and zinc in serum in chronic arterial occlusion of the lower limbs

Haptoglobin genotypes polymorphism as a risk factor for subclinical atherosclerosis in beta-thalassemia major children; a single center Egyptian study

Background/Objectives Haptoglobin (Hp) is an antioxidant protein. Its genotypic polymorphism had been proposed to influence vascular complications among diabetics, but no data are available about this association among thalassemia patients so far. We have investigated the assumption of an association between Hp genotypes and subclinical atherosclerosis among beta-thalassemia major (TM) children. Methods One hundred beta-TM children and 70 matched healthy controls were included. Serum ferritin level and fasting lipid profile were assayed. Haptoglobin genotyping was determined by amplification gel electrophoresis. Carotid intima media thickness (cIMT) was measured using high resolution ultrasound. Results The relative distribution of the three Hp genotypes among thalassemia group and the control group were 18 and 14.3% for Hp1-1; 38 and 37.1% for Hp2-1; and 44 and 48.6% for Hp2-2 respectively. There was no significant difference between patients and controls regarding Hp genotypes distribution. Hp2-2 genotype TM children had significantly higher cIMT compared to other genotypes (P < 0.0001). Elevated cIMT was significantly represented in Hp2-2 genotype patients (P < 0.0001) who had higher serum ferritin compared to their counterparts (P < 0.05). Hp2-2 patients were five times more likely to suffer from subclinical atherosclerosis than Hp1-1 and six times than Hp2-1 genotype patients (P = 0.008 and 0.001, respectively); a difference that persisted significant after adjustment for some risk factors compared to Hp2-1 patients (OR 3.96; P = 0.02). Conclusions Hp2-2 genotype is a significant predictor for premature atherosclerosis in TM children and confers them an increased risk for iron overload.

Effect of surgical treatment on lipid peroxidation parameters and antioxidant status in the serum of patients with peripheral arterial disease

The various risk factors for peripheral arterial disease (PAD) are almost identical to those for atherosclerosis and include abnormal levels of lipids or lipoproteins. Lipid peroxidation parameters and total antioxidant capacity in the serum of male patients with PAD before surgery as well as 3–5 days and 7–10 days after surgery were measured. We also compared these parameters with those in a group of patients receiving simvastatin therapy. Concentrations of lipid hydroperoxides (LOOHs) and malondialdehyde, the total antioxidant capacity (assessed by ferric reducing antioxidant power assay), concentration of thiol (-SH) groups, and ceruloplasmin activity were determined spectrophotometrically in PAD patients treated surgically (Group I) or pharmacologically (Group II). The patients before surgical treatment had significantly higher concentrations of malondialdehyde but lower ceruloplasmin activity than those observed in Group II, treated with simvastatin. No significant differences before surgery in ferric reducing antioxidant power or thiol concentrations were found between the two groups. However, in Group I, both ferric reducing antioxidant power and thiol group concentrations decreased 3–5 days postoperatively, and ceruloplasmin activity increased 7–10 days after surgical treatment. The presented results demonstrate diverse oxidative stress responses to surgical treatment and confirm the beneficial effects of statin therapy in PAD.

Influence of copper, iron, zinc and fe (3) (+) haemoglobin levels on the etiopathogenesis of chronic calcific pancreatitis--a study in patients with pancreatitis

Chronic pancreatitis is a serious condition associated with severe abdominal pain, and a significant percentage of patients progresses to irreversible calcification in pancreas. The present study evaluates the degree to which the levels of trace elements, copper, iron, selenium, zinc and haemoglobin-Fe(3+), in blood, serum and pancreas have any role to play in the calcification process associated with fibrosis in pancreas. Twenty-seven calcific (CCP) and 23 non-calcific chronic pancreatitis (CP) patients and equal number of age- and sex-matched normal volunteers (50) were enrolled in the study. Surgically removed pancreatic tissue and blood samples were analysed for copper, iron, selenium, zinc, protein, collagen and lipid peroxidation products in terms of malondialdehyde, protein carbonyls, glutathione, methemoglobin, methemoglobin reductase and ceruloplasmin activity levels. We could find that the pancreatic tissue levels of copper, iron, protein and collagen contents were significantly elevated in CCP patients when compared to CP patients. Serum levels of copper, free ionic copper and iron were also elevated in CCP patients. The serum and the pancreatic tissue level of zinc and selenium showed a significant decrease in CCP patients. The level of methemoglobin was elevated more significantly with the concomitant decline in the activity of methemoglobin reductase. There was a positive correlation between the pancreatic level of copper and iron with the collagen and protein levels. The results of the present study revealed that the levels of copper and iron, the pro-oxidants and zinc and selenium may influence calcification process in CCP patients. Hypoxia-related tissue injury due to the formation of oxidised haemoglobin may also contribute to the pathogenesis of calcification in pancreas.

Oxidation of nitroxyl anion to nitric oxide by copper ions

1. This study made use of a nitric oxide-sensitive electrode to examine possible means of generating nitric oxide from nitroxyl anion (NO(-)) released upon the decomposition of Angeli's salt. 2. Our results show that copper ions (from CuSO(4)) catalyze the rapid and efficient oxidation of nitroxyl to nitric oxide. Indeed, the concentrations of copper required to do so (0.1 - 100 microM) are roughly 100-times lower than those required to generate equivalent amounts of nitric oxide from S-nitroso-N-acetyl-D,L-penicillamine (SNAP). 3. Experiments with ascorbate (1 mM), which reduces Cu(2+) ions to Cu(+), and with the Cu(2+) chelators, EDTA and cuprizone, and the Cu(+) chelator, neocuproine, each at 1 mM, suggest that the oxidation is catalyzed by copper ions in both valency states. 4. Some compounds containing other transition metals, i.e. methaemoglobin, ferricytochrome c and Mn(III)TMPyP, were much less efficient than CuSO(4) in catalyzing the formation of nitric oxide from nitroxyl, while FeSO(4), FeCl(3), MnCl(2), and ZnSO(4) were inactive. 5. Of the copper containing enzymes examined, Cu-Zn superoxide dismutase and ceruloplasmin were weak generators of nitric oxide from nitroxyl, even at concentrations (2500 and 30 u ml(-1), respectively) vastly greater than are present endogenously. Two others, ascorbate oxidase (10 u ml(-1)) and tyrosinase (250 u ml(-1)) were inactive. 6. Our findings suggest that a copper-containing enzyme may be responsible for the rapid oxidation of nitroxyl to nitric oxide by cells, but the identity of such an enzyme remains elusive.