N-acetylcysteine exerts protective effects and prevents lung redox imbalance and peroxynitrite generation in endotoxemic rats.

The aim of this study was to determine in endotoxemic rats the effects of N-acetylcysteine on lung redox imbalance and plasma peroxynitrite generation. Eighty male Wistar rats were divided in two sets of five experimental groups. Six hours after vehicle (Control group: isotonic NaCl sterile solution i.

Effect of estrogen and angiotensin-converting enzyme inhibitor on vascular remodeling in ovariectomized spontaneously hypertensive rats.

Objective: The present study evaluated whether estrogen influences the effect of angiotensin-converting enzyme inhibition in preventing the vascular remodeling induced by hypertension and also investigated the signal mechanism involved in that effect.

Design: Ten-week-old female spontaneously hypertensive rats were ovariectomized (OVX) and randomly assigned to the groups: untreated OVX and treated with 17beta-estradiol (estradiol, 1.5 mg) and/or captopril (5 mg/kg/day).

17Beta-oestradiol enhances the acute hypotensive effect of captopril in female ovariectomized spontaneously hypertensive rats.

The objective of this study was to investigate whether the acute haemodynamic effects of angiotensin-converting enzyme inhibition with captopril could be enhanced by oestrogen administration, and then to evaluate the mechanisms involved in this enhancement. All experiments were performed in 18-week-old female spontaneously hypertensive rats arranged in three experimental groups: intact; ovariectomized (OVX); and ovariectomized plus treatment with 17beta-oestradiol (OVX + E2). These groups were used to evaluate the effects of captopril administration alone, or following bradykinin B2 receptor blockade or nitric oxide synthase inhibition, on a number of haemodynamic parameters (mean arterial pressure, cardiac index, vascular resistance and heart rate).

Effects of oestrogen treatment and angiotensin-converting enzyme inhibition on the microvasculature of ovariectomized spontaneously hypertensive rats.

We investigated the role of oestrogen in the function and structure of the microcirculation of female spontaneously hypertensive rats (SHRs), and evaluated the effect of 17beta-oestradiol on their cardiovascular response to pharmacological agents that block the formation of angiotensin II. Ten-week-old SHRs were randomly assigned to the following groups: intact, ovariectomized, and ovariectomized treated with 17beta-oestradiol (1.5 mg delivered over 60 days) and/or captopril (5 mg kg(-1) day(-1) for 8 weeks).

17beta-estradiol exerts a beneficial effect on coronary vascular remodeling in the early stages of hypertension in spontaneously hypertensive rats.

Objective: Estrogens may induce cardioprotective effects and prevent neointima formation in response to vascular injury in vivo. The present study evaluated the effect of 17beta-estradiol on myocardial arterial remodeling and on vascular mitogen-activated protein kinase expression in experimental hypertension.

Design: The experiments were performed in intact female spontaneously hypertensive rats (SHR), in SHR that were ovariectomized at 10 or 25 weeks of age, and in ovariectomized SHR that were supplemented with 17 beta-estradiol (OVX + E2, 1.

Renal ischemia induces an increase in nitric oxide levels from tissue stores.

Tissue nitric oxide (NO) levels increase dramatically during ischemia, an effect that has been shown to be partially independent from NO synthases. Because NO is stored in tissues as S-nitrosothiols and because these compounds could release NO during ischemia, we evaluated the effects of buthionine sulfoximine (BSO; an intracellular glutathione depletor), light stimulation (which releases NO, decomposing S-nitrosothiols), and N-acetyl-L-cysteine (a sulfhydryl group donor that repletes S-nitrosothiols stores) on the changes in outer medullary NO concentration produced during 45 min of renal artery occlusion in anesthetized rats. Renal ischemia increased renal tissue NO concentration (+223%), and this effect was maintained along 45 min of renal arterial blockade.

Oxidative stress in critically ill patients with systemic inflammatory response syndrome.

Objective: To evaluate whether critically ill patients with systemic inflammatory response syndrome, on admission to an intensive care unit, had more severe oxidative stress than those without this syndrome.

Design: A prospective, cohort study.

Setting: A mixed medical and surgical adult intensive care unit with 12 beds.

Hemodynamic state and the role of angiotensin II in ovarian hyperstimulation syndrome in the rabbit.

Objective: To investigate the hemodynamic state in the ovarian hyperstimulation syndrome (OHSS) in the rabbit model and to determine the role of angiotensin II in the pathophysiology of this syndrome.

Design: Experimental study.

Setting: Physiology laboratory.