Metyrapone improves endothelial dysfunction in patients with treated depression.

Objectives: This study sought to examine the effect of metyrapone on endothelial dysfunction in patients with treated recurrent major depression.

Background: Depression is an independent risk factor for the development of coronary heart disease, and patients with depression have endothelial dysfunction, an atherogenic abnormality. This abnormality may be attributable to abnormal hypothalamic-pituitary-adrenal (HPA) axis function, a feature of depression, resulting in increased exposure to cortisol.

Baroreflex sensitivity is reduced in depression.

Objectives: Depression is independently associated with increased cardiovascular morbidity and mortality, including sudden cardiac death, and this risk is observed even in patients who have been successfully treated for depression. Recent studies have emphasized the importance of impaired baroreceptor sensitivity (BRS) as a predisposing factor for sudden death in patients with manifest cardiac disease. Our objective was to test the hypothesis that BRS is impaired in subjects with depression in remission and with no other cardiac risk factors.

Inhibition of cortisol production with metyrapone prevents mental stress-induced endothelial dysfunction and baroreflex impairment.

Objectives: This study was designed to investigate the role of cortisol in stress-induced endothelial dysfunction and impaired baroreflex sensitivity (BRS) by blocking cortisol production with metyrapone before subjecting healthy volunteers to mental stress.

Background: Mental stress raises cortisol levels and is associated with increased coronary heart disease (CHD) morbidity and mortality, especially from sudden cardiac death. It also causes endothelial dysfunction and impaired BRS.

Effects of exogenous and endogenous natriuretic peptides on forearm vascular function in chronic heart failure.

Objective: Natriuretic peptides (NPs) reduce central venous pressure in patients with chronic heart failure (cHF) despite attenuation of arterial, renal, and humoral effects. This suggests a preserved venodilator response. This study had 4 aims: to compare the venodilator effects of human NPs in patients with cHF; to assess the contribution of basal ANP and BNP levels to regulation of forearm vascular volume (FVV); to test the hypothesis that venous ANP responsiveness is preserved in cHF; and to assess the involvement of endothelial nitric oxide-synthase (eNOS) in NP-induced vascular effects.

Inhibition of platelet aggregation by nitric oxide donors improves with rest.

It has been suggested that the platelets of patients with acute coronary syndromes (ACS) exist in a more activated state than those of patients with stable coronary heart disease (CHD) or healthy individuals. "Platelet nitrate responsiveness" (PNR) has been suggested as a measure of platelet activation, and has been shown to be reduced in both ACS and stable CHD. We examined the effect of a short period of undisturbed supine rest, an intervention aimed at reducing levels of "stress", on PNR.

Atrial natriuretic peptide regulates regional vascular volume and venous tone in humans.

Objective: To date, the contribution of basal atrial natriuretic peptide (ANP) levels to resting vascular function in humans is unknown. In the present study we sought to investigate the role of ANP in regulating regional vascular volume and venous tone in healthy subjects.

Methods And Results: We used radionuclide plethysmography to examine the effects of ANP and the ANP-receptor antagonist A71915 on forearm vascular volume.

Supine rest reduces platelet activation and aggregation.

Platelet activation and aggregation are central processes in acute coronary syndromes and myocardial infarction, and are stimulated by physical and mental stress. However, it is not known if and to what extent the "ordinary" stress inherent in a person's daily routine contributes to platelet activation and aggregation. We measured platelet activation and aggregation in 12 healthy non-smokers, before and after 45 min supine rest in a calm environment.