We tested the hypothesis that unanesthetized rats exhibit ventilatory long-term facilitation (LTF) after intermittent, but not continuous, hypoxia. Minute ventilation (VE) and carbon dioxide production (VCO(2)) were measured in unanesthetized, unrestrained male Sprague-Dawley rats via barometric plethysmography before, during, and after exposure to continuous or intermittent hypoxia. Hypoxia wa...

Our study was designed to determine if central nervous system (CNS) serotonin is required for the induction of ventilatory long-term facilitation (LTF) in intact, spontaneously breathing mice. Nineteen tryptophan hydroxylase 2-deficient (Tph2(-/-)) mice, devoid of serotonin in the CNS, and their wild-type counterparts (Tph2(+/+)) were exposed to intermittent hypoxia each day for 10 consecutive ...

BACKGROUND Xanthine oxidase is a major source of superoxide in the vascular endothelium. Previous work in humans demonstrated improved conduit artery function following xanthine oxidase inhibition in patients with obstructive sleep apnea. OBJECTIVES To determine whether impairments in endothelium-dependent vasodilation produced by exposure to chronic intermittent hypoxia are prevented by in v...

1471 Intermittent Hypoxia Elevates Cobalt Levels in Brain—Veasey et al INTRODUCTION Occurring in 3-5% of adults in developed countries, obstructive sleep apnea (OSA) involves intermittent, sleep state-dependent, brief reductions or cessations in ventilation.1 Each disruption is associated with a partial desaturation of hemoglobin followed by reoxygenation. The brain is particularly vulnerable t...

This study was designed to (1) investigate the effects of acute short-duration intermittent hypoxia on musclemRNAand microRNAexpression levels; and (2) clarify the mechanisms by which short-duration intermittent hypoxia improves endurance capacity. Experiment-1: Male mice were subjected to either acute 1-h hypoxia (12% O2), acute short-duration intermittent hypoxia (12% O2for 15 min, room air f...

Intermittent hypoxia due to sleep apnea syndrome is associated with cardiovascular diseases. However, the precise mechanisms by which intermittent hypoxic stress accelerates cardiovascular diseases are largely unclear. The aim of this study was to investigate the role of gp91(phox)-containing NADPH oxidase in the development of left ventricular (LV) remodeling induced by intermittent hypoxic st...

Mitchell, Gordon S., Tracy L. Baker, Steven A. Nanda, David D. Fuller, Andrea G. Zabka, Brad A. Hodgeman, Ryan W. Bavis, Kenneth J. Mack, and E. B. Olson, Jr. Invited Review: Intermittent hypoxia and respiratory plasticity. J Appl Physiol 90: 2466–2475, 2001.— Intermittent hypoxia elicits long-term facilitation (LTF), a persistent augmentation (hours) of respiratory motor output. Considerable r...

Obstructive sleep apnea (OSA) is associated with transient elevation of muscle sympathetic nerve activity (MSNA) during apneic events, which often produces elevated daytime MSNA in OSA patients. Hypoxia is postulated to be the primary stimulus for elevated daytime MSNA in OSA patients. Therefore, we studied the effects of 20 min of intermittent voluntary hypoxic apneas on MSNA during 180 min of...

Respiratory insufficiency is the leading cause of death after high-cervical spinal cord injuries (SCIs). Although respiratory motor recovery can occur with time after injury, the magnitude of spontaneous recovery is limited. We hypothesized that partial respiratory motor recovery after chronic cervical SCI could be strengthened using a known stimulus for spinal synaptic enhancement, intermitten...

STUDY OBJECTIVES A pilot study to examine the effects of intermittent nocturnal hypoxia on sleep, respiration and cognition in healthy adult humans. METHODS Participants were eight healthy, non-smoking subjects (four male, four female), mean age of 26.4+/-5.2 years, and BMI 22.3+/-2.6 kg/m(2), exposed to 9h of intermittent hypoxia between the hours of 10 P.M. and 7 A.M. for 28 consecutive nig...