Decreased vascular contractility induced by hemin is associated with a reduced rho-kinase activity.

Objectives: In this study, the role of rho-kinase activity in the modulation of vascular contractility induced by hemin, a heme oxygenase inducer, was investigated.

Methods: Aortic rings from Wistar rats were incubated in physiological saline solution (PSS) containing hemin at 10-(4) M for six hours then contracted with phenylephrine, and a dose-response curve was established. The effect of Y-27632, a rho-kinase inhibitor, on the relaxation of the pre-contracted aortic rings was then studied.

Adaptative modifications of right coronary myocytes voltage-gated K+ currents in rat with hypoxic pulmonary hypertension.

Chronic hypoxia (CH)-induced pulmonary hypertension (PHT) is well known to alter K+ channels in pulmonary myocytes. PHT induces right ventricle hypertrophy that increases oxygen demand; however, coronary blood flow and K+ channel adaptations of coronary myocytes during PHT remain unknown. We determined whether CH and PHT altered K+ currents and coronary reactivity and what impact they might have on right myocardial perfusion.

Dexfenfluramine does not worsen but moderates progression of chronic hypoxia-induced pulmonary hypertension.

This study shows for the first time, that dexfenfluramine, a 5-HT(2) receptor agonist, attenuates the development of chronic hypoxia-induced pulmonary hypertension. Chronic exposure to hypoxia, 4 weeks, induced hypoxic pulmonary hypertension in adult rat as haemodynamic and cardiac measurements showed significant modifications in right ventricle parameters (free wall right ventricle thickness; pulmonary acceleration time and velocity time integral) in chronic hypoxic control when compared to normoxic control animals. We observed that free wall right ventricle thickness and pulmonary velocity time integral were significantly less in chronic hypoxic rats treated with dexfenfluramine when compared to chronic hypoxic control rats.

Exercise and vasorelaxing effects of CO-releasing molecules in hypertensive rats.

Purpose: Because carbon monoxide (CO) has been reported able to induce relaxation, we aimed to investigate the effects of exercise training on the rat thoracic aorta responsiveness to a CO-releasing molecule (CORM), tricarbonyldichlororuthenium ([Ru(CO)3Cl2]2).

Methods: Male Wistar rats (N = 32) were divided in hypertensive and normotensive groups using the two-kidney, one-clip model of Goldblatt or SHAM surgery. Hypertensive and normotensive groups were assigned to an exercise training protocol on a level treadmill over a 10-wk period or were assigned to remain sedentary.

Prognostic value of 24-hour ambulatory blood pressure measurement for the onset of atrial fibrillation in treated patients with essential hypertension.

This study retrospectively determined the prognostic variables of blood pressure by 24-hour ambulatory blood pressure measurement in relation to onset of atrial fibrillation in treated patients who had essential hypertension and analyzed the class effect of antihypertensive management on the nonoccurrence of this supraventricular arrhythmia.