BACKGROUND Alterations in pulmonary blood flow are often associated with the initiation and progression of pulmonary vascular disease. However, the cellular mechanisms involved in mediating flow effects in the pulmonary circulation remain unclear. Depending on the disease condition, flow may be extremely low or high. We therefore examined effects of pathologically low and high flow on endotheli...

Idiopathic pulmonary arterial hypertension (IPAH) is a fatal disease characterised by elevated blood pressure in the pulmonary circulation. Initial vasoconstriction, proliferation of pulmonary arterial smooth muscle cells (PASMC) and increased deposition of extracellular matrix (ECM) contribute to pathological remodelling of pulmonary arterioles in IPAH. Glycosaminoglycans (GAGs), components of...

Several pathological conditions, including hypertension, atherosclerosis, diabetes, ischemia/reperfusion injury and nicotine-induced vasculopathy, are associated with vascular endothelial dysfunction characterized by altered secretory output of endothelial cells. Therefore there is a search for molecules and interventions that could restore endothelial function, in particular augmenting NO prod...

The effects of Mg(2+) and nifedipine (Nif) on vasoconstriction and Ca(2+) transients were studied in intact, pressurized rat mesenteric arteries with myogenic tone. Changes in cytosolic Ca(2+) concentration ([Ca(2+)](cyt)) were measured with confocal microscopy in fluo 4-AM loaded, individual myocytes. Myogenic tone was abolished by 10 mM Mg(2+) or 0.3 microM Nif. Contractions induced by 75 mM ...

Zhang, Jin, W. Gil Wier, and Mordecai P. Blaustein. Mg2 blocks myogenic tone but not K -induced constriction: role for SOCs in small arteries. Am J Physiol Heart Circ Physiol 283: H2692–H2705, 2002. First published August 15, 2002; 10.1152/ajpheart.00260.2002.—The effects of Mg2 and nifedipine (Nif) on vasoconstriction and Ca2 transients were studied in intact, pressurized rat mesenteric arteri...

The arterial baroreflex mediates changes in arterial pressure via reflex changes in cardiac output (CO) and regional vascular conductance, and the relative roles may change between rest and exercise and across workloads. Therefore, we quantified the contribution of CO and regional vascular conductances to carotid baroreflex-mediated increases in mean arterial pressure (MAP) at rest and during m...

Previous studies showed noxious unilateral forepaw electrical stimulation surprisingly evoked negative blood-oxygenation-level-dependent (BOLD), cerebral blood flow (CBF), and cerebral blood volume (CBV) fMRI responses in the bilateral striatum whereas the local neuronal spike and c-Fos activities increased. These negative responses are associated with vasoconstriction and appeared to override ...

Although endothelin-1 (ET-1) induces vasoconstriction, it remains unknown whether 17beta-estradiol (E(2)) treatment following trauma-hemorrhage alters these ET-1-induced vasoconstrictive effects. In addition, the role of the specific estrogen receptor (ER) subtypes (ER-alpha and ER-beta) and the endothelium-localized downstream mechanisms of actions of E(2) remain unclear. We hypothesized that ...

Reportedly, during spinal anesthesia, the shivering threshold is reduced approximately 1 degree C but the vasoconstriction threshold remains normal. Such divergence between the shivering and vasoconstriction thresholds is an unusual pattern of thermoregulatory impairment and suggests that the mechanisms of impairment during regional anesthesia may be especially complex. Accordingly, we sought t...

Endothelial dysfunction is a pathological status of the vascular system, which can be broadly defined as an imbalance between endothelium-dependent vasoconstriction and vasodilation. Endothelial dysfunction is a key event in the progression of many pathological processes including atherosclerosis, type II diabetes and hypertension. Previous reports have demonstrated that pro-inflammatory/immuno...