Effects of Chronic Exposure to Mercury on Angiotensin-Converting Enzyme Activity and Oxidative Stress in Normotensive and Hypertensive Rats.

Background: Mercury's deleterious effects are associated with increased cardiovascular risk.

Objective: To determine whether chronic exposure to inorganic mercury increases the activity of angiotensin-converting enzyme and its relationship with oxidative stress in several organs and tissues.

Methods: We studied male Wistar and spontaneously hypertensive rats (SHR) (3-month-old) exposed or not to HgCl2 for 30 days.

Influence of ovariectomy in the right ventricular contractility in heart failure rats.

Background: Clinical studies in postmenopausal women suggest that female hormones play an important role in maintaining healthy cardiovascular conditions. The objective of this study was to evaluate the influence of ovarian hormones in the right ventricle contractility in heart failure (HF) rats following myocardial infarction (MI).

Methods: Female Wistar rats were divided into four groups: healthy ovariectomized (OVX), ovariectomized with HF (OVX-HF), HF, and sham operated (SHAM).

Myocardial infarction increases reactivity to phenylephrine in isolated aortic rings of ovariectomized rats.

Clinical studies demonstrated that the incidence of cardiovascular disease is low in premenopausal women, rises in postmenopausal women, and is reduced to premenopausal levels in postmenopausal women who receive estrogen therapy. The interaction between gender and myocardial infarction indicates that the survival advantage of women is modified by the occurrence of myocardial infarction. Therefore, the effect of myocardial infarction on mortality is greater in women than men.