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Very fast-growing (VFG) broiler chickens tend to have marked right ventricular hypertrophy when compared with slower growing chickens. We hypothesized that, in the setting of rapid growth, a hypoxic stimulus would cause greater pulmonary hypertension and right ventricular hypertrophy (RVH). We have studied the relationship between artial oxygenation (SaO2),(More)
RhoA GTPase mediates a variety of cellular responses, including activation of the contractile apparatus, growth, and gene expression. Acute hypoxia activates RhoA and, in turn, its downstream effector, Rho-kinase, and previous studies in rats have suggested a role for Rho/Rho-kinase signaling in both acute and chronically hypoxic pulmonary vasoconstriction.(More)
BACKGROUND Data from a pilot study suggested that noetic therapies-healing practices that are not mediated by tangible elements-can reduce preprocedural distress and might affect outcomes in patients undergoing percutaneous coronary intervention. We undertook a multicentre, prospective trial of two such practices: intercessory prayer and music, imagery, and(More)
Vascular remodeling, rather than vasoconstriction, is believed to account for high vascular resistance in severe pulmonary arterial hypertension (PAH). We have found previously that acute Rho kinase inhibition nearly normalizes PAH in chronically hypoxic rats that have no occlusive neointimal lesions. Here we examined whether Rho kinase-mediated(More)
1. At 6 weeks of age, the time of most rapid body growth, fast growing broiler chickens showed more right ventricular hypertrophy than slower growing chickens. 2. The degree of right ventricular hypertrophy was directly related to blood haematocrit and indirectly related to arterial oxygen saturation (estimated in the chickens using an ear oximeter designed(More)
We have found in chronically hypoxic rats that acute intravenous administration of the Rho kinase inhibitor Y-27632 nearly normalizes the pulmonary hypertension (PH) but has no pulmonary vascular selectivity. In this study, we tested if oral or inhaled Y-27632 would be an effective and selective pulmonary vasodilator in hypoxic PH. Although acute oral(More)
Previous studies suggest that while lung angiotensin converting enzyme (ACE) activity is reduced during chronic hypoxia, inhibitors of ACE attenuate hypoxic pulmonary hypertension. In an attempt to explain this paradox we investigated the possibility that whole lung ACE activity may not reflect local pulmonary vascular ACE expression. The experimental(More)
Although angiotensin converting enzyme (ACE) inhibitors are known to attenuate the development of hypoxic pulmonary hypertension in rats, the precise mechanism of this protective effect remains unknown. Thus we utilized specific angiotensin II (ANG II)-receptor antagonists to investigate whether ANG II is involved directly in the hemodynamic and structural(More)
Nitric oxide plays an important role in modulating pulmonary vascular tone. All three isoforms of nitric oxide synthase (NOS), neuronal (nNOS, NOS I), inducible (iNOS, NOS II), and endothelial (eNOS, NOS III), are expressed in the lung. Recent reports have suggested an important role for eNOS in the modulation of pulmonary vascular tone chronically;(More)
Aquaporin-2 (AQP2) mediates vasopressin-regulated collecting duct water permeability. Chronic heart failure (CHF) is characterized by abnormal renal water retention. We hypothetized that upregulation of aquaporin-2 water channel could account for the water retention in CHF. Male rats underwent either a left coronary artery ligation, a model of CHF, or were(More)