Chronic hypoxia induces pulmonary hypertension and vascular remodeling, which are clinically relevant to patients with chronic obstructive pulmonary disease (COPD) associated with a decreased level of nitric oxide (NO). Oxidative stress and inflammation play important roles in the pathophysiological processes in COPD. We examined the hypothesis that daily administration of melatonin (10 mg/kg) ...

OBJECTIVE Hypobaric hypoxia, physical and psychosocial stress may influence key cardiovascular parameters including blood pressure (BP) and pulse pressure (PP). We investigated the effects of mild hypobaric hypoxia exposure on BP and PP reactivity to mental and physical stress and to passive elevation by cable car. METHODS 36 healthy volunteers participated in a defined test procedure consist...

A periodic increase in blood pressure (BP) occurs during apneic episodes in patients with obstructive sleep apnea (OSA). Several factors including hypoxemia and an increase in heart rate (HR) were reported to be responsible for this increased BP. To examine the contribution of these two factors in increasing BP, 35 healthy male subjects (mean age±SD= 23.64±3.80) were studied in three experi...

This study determined if altered vascular prostacyclin (PGI(2)) and/or thromboxane A(2) (TxA(2)) production with reduced Po(2) contributes to impaired hypoxic dilation of skeletal muscle resistance arterioles of obese Zucker rats (OZRs) versus lean Zucker rats (LZRs). Mechanical responses were assessed in isolated gracilis muscle arterioles following reductions in Po(2) under control conditions...

Craniofacial anomalies can arise from both genetic and environmental factors, including prenatal hypoxia. Recent clinical evidence correlates hypoxia to craniofacial malformations. However, the mechanisms by which hypoxia mediates these defects are not yet understood. We examined the cellular mechanisms underlying malformations induced by hypoxia using a chicken (Gallus gallus) embryo model. Eg...

The process of protein modification by adding or detaching small ubiquitin-like modifiers (SUMO) proteins, called SUMOylation, contributes to the regulation of numerous processes in eukaryotic cells. SUMOylation also represents a key response and adaption mechanism to different forms of metabolic stress. The central nervous system (CNS) and neurons in particular are highly susceptible to hypoxi...

Hypoxia is a common cause of kidney injury and a major issue in kidney transplantation. Mitogen-activated protein kinases (MAPKs) are involved in the cellular response to hypoxia, but the precise roles of MAPKs in renal cell reaction to hypoxic stress are not well known yet. This work was conducted to investigate the regulation of ERK1/2 and p38 and their signaling-relevant molecules in kidney ...

Neonatal brain hypoxic-ischemic injury represents a serious health care and socio-economical problem since it is one of the most common causes of mortality and morbidity of newborns. Neonatal hypoxic-ischemic encephalopathy is often associated with signs of perinatal asphyxia, with an incidence of about 2-4 per 1,000 live births and mortality rate up to 20%. In about one half of survivors, cere...

Background: Alveolar hypoxia induces monophasic pulmonary vasoconstriction in vivo, biphasic vasoconstriction in the isolated pulmonary artery, and controversial responses in the isolated perfused lung. Pulmonary vascular responses to sustained alveolar hypoxia have not been addressed in the isolated perfused rat lung. In this study, we investigated the effect of sustained hypoxic ventilation o...

Background—Previous studies in isolated cardiac myocytes have shown that tumor necrosis factor (TNF)-a provokes increased expression of 27and 70-kD stress proteins as well as manganese superoxide dismutase, suggesting that TNF-a might play a role in mediating stress responses in the heart. Methods and Results—To determine whether TNF-a stimulation would protect isolated cardiac myocytes against...