[Some markers of oxidative stress in hypertension induced by chronic inhibition of nitric oxide synthase].

The aim of this study was to estimate some markers of oxidative stress in plasma and kidney of rats with experimental hypertension induced by chronic inhibition of nitric oxide synthase (NOS) by L-NAME (methyl ester of N-nitro-L-arginin). We investigated the concentration of lipid peroxidation products such as aldehydes, lipid hydroperoxides and the total antioxidant status (FRAP) in plasma. We also measured the concentration of reduced SH groups in plasma, renal cortex and medulla.

[Oxidative stress in hypertension].

Reactive oxygen species (ROS) are involved in the pathogenesis of many cardiovascular diseases such as hypertension. In the circulation, ROS are generated by all vascular cells, i.e.

[Heme oxygenase and carbon monoxide in the physiology and pathology of the cardiovascular system].

Heme oxygenase (HO) degrades heme to carbon monoxide (CO), ferrous ions, and the bile pigment biliverdin, which is subsequently reduced to the other important bile pigment, bilirubin, by biliverdin reductase. Fe2+ liberated from the heme molecule upregulates ferritin production, and bile pigments are potent endogenous antioxidants. The HO enzyme exists in three isophorms: HO-1 is expressed at low levels under physiological conditions, but is induced by numerous factors, including oxidative stress, inflammation, nitric oxide, an elevated level of substrate, and hypoxia.

Oxidative stress, nitric oxide production, and renal sodium handling in leptin-induced hypertension.

Chronic hyperleptinemia induces arterial hypertension in experimental animals and may contribute to the development of hypertension in obese humans; however, the mechanism of hypertensive effect of leptin is not completely elucidated. We investigated the effect of leptin on whole-body oxidative stress, nitric oxide production, and renal sodium handling. The study was performed on male Wistar rats divided into 3 groups: 1) control, fed standard chow ad libitum, 2) leptin-treated group, receiving leptin injections (0.

Adrenomedullin--what do we know 10 years since its discovery?

Adrenomedullin (ADM) is a 52-amino acid peptide with structural homology to calcitonin gene-related peptide (CGRP) initially isolated from human pheochromocytoma. ADM is synthesized by many mammalian tissues including the adrenal medulla, endothelial and vascular smooth muscle cells, myocardium and central nervous system. ADM binds to plasma membrane receptors composed of calcitonin receptor-like receptor (CRLR), a member of serpentine receptor superfamily, and receptor activity modifying protein (RAMP) type 2 or 3.

Stimulatory effect of leptin on nitric oxide production is impaired in dietary-induced obesity.

Objective: We investigated the effect of leptin on nitric oxide production in lean and rats made obese by a high-calorie diet.

Research Methods And Procedures: The animals were placed in metabolic cages, and urine was collected in 2-hour periods after leptin (1 mg/kg intraperintoneally) or vehicle administration. Blood was obtained 0.

Effect of 3-hydroxy-3-methylglutarylcoenzyme A reductase inhibitors (statins) on tissue paraoxonase 1 and plasma platelet activating factor acetylhydrolase activities.

The authors investigated the effect of pravastatin and fluvastatin on paraoxonase 1 (PON1) activity in plasma, liver, heart, and kidney, as well as on plasma platelet activating factor acetylhydrolase (PAF-AH) in the rat. The animals received pravastatin at doses of 4 and 40 mg/kg/d or fluvastatin at doses of 2 or 20 mg/kg/d for 3 weeks. Fluvastatin (20 mg/kg/d) reduced plasma PON1 activity toward paraoxon and phenyl acetate by 23.

Leptin decreases plasma paraoxonase 1 (PON1) activity and induces oxidative stress: the possible novel mechanism for proatherogenic effect of chronic hyperleptinemia.

Obesity is an important risk factor of atherosclerosis; however, the mechanism of proatherogenic effect of obesity is not definitely established. Recent studies suggest an important role of leptin in obesity associated complications. We investigated the effect of chronic hyperleptinemia on two antioxidant enzymes contained in plasma lipoproteins: paraoxonase 1 (PON1) and platelet activating factor-acetylhydrolase (PAF-AH).

Differential effect of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors on plasma paraoxonase 1 activity in the rat.

Statins (3-hydroxy-3-methylglutarylcoenzyme A reductase inhibitors), apart from lowering plasma cholesterol, modulate other processes involved in atherogenesis. The aim of this study was to investigate the effect of a natural statin, pravastatin, and of the synthetic one, fluvastatin, on plasma paraoxonase 1 (PON1), the antioxidant enzyme contained in plasma high-density lipoproteins. The adult male Wistar rats received either pravastatin (4 or 40 mg/kg/day) or fluvastatin (2 or 20 mg/kg/day) for 3 weeks.

[Peroxisome proliferator-activated receptors (PPAR) in pathophysiology of the circulatory system and prospective use of agonists of these receptors in therapy].

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors which regulate the expression of target genes. Three types of PPAR have been identified: PPAR alpha, PPAR beta/delta and PPAR gamma. The known endogenous PPAR ligands are polyunsaturated fatty acids and eicosanoids, such as 15-deoxy-delta 12,14-prostaglandin J2 and leukotriene B4.

[Serum paraoxonase activity, total antioxidant potential and lipid peroxidation products in children with bronchial asthma exacerbation].

The aim of this study was to investigate serum paraoxonase (PON) activity, total antioxidant capacity and serum level of lipid peroxidation products in children with exacerbated bronchial asthma. The study was performed in 23 children (17 males and 6 females, age 3-17 years) admitted to the hospital with asthma exacerbation. Aliquots of serum were collected before administration of any treatment.

Cerivastatin modulates plasma paraoxonase/arylesterase activity and oxidant-antioxidant balance in the rat.

Statins (3-hydroxy-3-methylglutarylcoenzyme A reductase inhibitors), apart from lowering plasma cholesterol, modulate other processes involved in atherogenesis. Paraoxonase (PON), contained in plasma high density lipoproteins, protects plasma lipoproteins from oxidative damage and is a potentially atheroprotective enzyme. We investigated the effect of cerivastatin on oxidant-antioxidant balance and plasma PON activity.