EFFECT OF BENZENE TREATMENT ON HEPATIC LIPID-PEROXIDATION AND ANTIOXIDANT ENZYME-ACTIVITIES IN MICE

The effect of acute and chronic benzene treatment on lipid peroxidation and antioxidant system was investigated in liver of mice. Malondialdehyde (MDA) and diene conjugate levels were found increased in liver homogenates and microsomes of chronically benzene treated group whereas no change was observed in acute benzene injected group. However, glutathione (GSH) levels remained unchanged in liver homogenates of all the benzene treated groups. We also found marked increases in cytosolic total (selenium-dependent + nonselenium-dependent) glutathione peroxidase (GSH-Px), glutathione transferase (GST) activities whereas selenium-dependent GSH-Px and superoxide dismutase (SOD) activities did not change after chronic benzene treatment. Increased enzyme activities are estimated as an adaptation to lipid peroxidation stimulated by chronic benzene administration. Our results suggest that benzene metabolism causes free radical induced lipid peroxidation in the liver and most probably hepatic microsomes play a significant role in this metabolism

Lipid peroxidation and antioxidant enzymes in livers and brains of aged rats

The contribution of free radical damage to aging in the liver and brain is still controversial. There have also been several reports with conflicting results on the antioxidant system during aging. In this study, we investigated endogenous lipid peroxide levels in the liver and brain tissues of rats aged 6 and 22 months together with ascorbate-induced lipid peroxidation. Also, superoxide dismutase (SOD) and glutathione peroxidase (GPx), the main antioxidant enzymes were assayed. Although ascorbate-induced lipid peroxide levels remained unchanged in aged animals, hepatic lipid peroxidation was seen to be elevated. Glutathione (GSH) content was found to be decreased, but SOD and GPx remained unchanged. No apparent difference in any parameter in brain tissues was observed in the old group. (C) 1997 Elsevier Science Ireland Ltd

Mitochondrial lipid peroxidation and antioxidant system in aged rats

Mitochondria are especially important in cellular senescence since reactive oxygen species (ROS) have been found to be generated constantly as an endogen threat. On the other hand, mitochondrial defence depends mainly on glutathione (GSH), superoxide dismutase (SOD) and glutathione peroxidase (GP(x)). In this study, liver and brain mitochondria of 6- and 22-month-old rats were investigated. Liver mitochondrial malondialdehyde (MDA) levels were found increased, whereas mitochondrial GSH was decreased. SOD activity has been observed elevated, whereas GP(x) was unchanged. However, brain mitochondrial MDA, GSH and SOD and GP(x) activites were found unchanged in old rats. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved

Intravenous NPA for the treatment of infarcting myocardium early: InTIME-II, a double-blind comparison on of single-bolus lanoteplase vs accelerated alteplase for the treatment of patients with acute myocardial infarction

Aims to compare the efficacy and safety of lanoteplase, a single-bolus thrombolytic drug derived from alteplase tissue plasminogen activator, with the established accelerated alteplase regimen in patients presenting within 6 h of onset of ST elevation acute myocardial infarction. Methods and Results 15 078 patients were recruited from 855 hospitals worldwide and randomized in a 2:1 ratio to receive either lanoteplase 120 KU. kg-1 as a single intravenous bolus, or up to 100 mg accelerated alteplase given over 90 min. The primary end-point was all-cause mortality at 30 days and the hypothesis was that the two treatments would be equivalent. By 30 days, 6.61% of alteplase-treated patients and 6.75% lanoteplase-treated patients had died (relative risk 1.02). Total stroke occurred in 1.53% alteplase- and 1.87% lanoteplase-treated patients (ns); haemorrhagic stroke rates were 0.64% alteplase and 1.12% lanoteplase (P=0.004). The net clinical deficit of 30-day death or non-fatal disabling stroke was 7.0% and 7.2%, respectively. By 6 months, 8.8% of alteplase-treated patients and 8.7% of lanoteplase-treated patients had died. Conclusion Single-bolus weight-adjusted lanoteplase is an effective thrombolytic agent, equivalent to alteplase in terms of its impact on survival and with a comparable risk-benefit profile. The single-bolus regimen should shorten symptoms to treatment times and be especially convenient for emergency department or out-of-hospital administration. (C) 2000 The European Society of Cardiology