Nitric oxide deficit in chronic intermittent hypoxia impairs large conductance calcium-activated potassium channel activity in rat hippocampal neurons.

Nitric oxide deficit in chronic intermittent hypoxia impairs large conductance calcium-activated potassium channel activity in rat hippocampal neurons. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

Nitric oxide deficit in chronic intermittent hypoxia impairs large conductance calcium-activated potassium channel activity in rat hippocampal neurons. Abstract Text:

Yung-Wui Tjong,Meifang Li,Ming-Wai Hung,Kun Wang,Man-Lung Fung,

Sleep apnea associated with chronic intermittent hypoxia (IH) impairs hippocampal functions but the pathogenic mechanisms involving dysfunction of nitric oxide (NO) and ionic channels remain unclear. We examined the hypothesis that hippocampal NO deficit impairs the activity of large conductance calcium-activated potassium (BK) channels in rats with chronic IH, mimicking conditions in patients with sleep apnea. A patch-clamp study was performed on hippocampal CA1 neurons acutely dissociated from IH and control rats. The levels of endogenous NO and intracellular calcium in the CA1 region of the hippocampal slices were measured respectively by electrochemical microsensors and spectrofluorometry. We found that the open probability of BK channels remarkably decreased in the CA1 pyramidal neurons in a time-dependent manner with the IH treatment, without changes in the unitary conductance and reversal potential. NO donors, SNP or DETA/NO, significantly restored the activity of BK channels in the IH neurons, which was prevented by blockade of S-nitrosylation with NEM or MTSES but not by inhibition of the cGMP pathway with ODQ or 8-bromo-cGMP. Endogenous NO levels were substantially lowered in the IH hippocampus during resting and hypoxia. Also, the level of protein expression of neuronal NO synthase was markedly lessened in the IH neurons with decreased intracellular calcium response to hypoxia. Collectively, the results suggest that the IH-induced NO deficit mediated by a down-regulation of the expression of neuronal NO synthase plays a causative role in the impaired activity of BK channels, which could account for the hippocampal injury in patients with sleep apnea.

Nitric oxide deficit in chronic intermittent hypoxia impairs large conductance calcium-activated potassium channel activity in rat hippocampal neurons. Publishing Authors By Initials

YW Tjong,M Li,MW Hung,K Wang,ML Fung,

For similar abstracts research abstracts see: abstracts research

PUBMED ID PMID:

MEDLINE DATE:

Nitric oxide deficit in chronic intermittent hypoxia impairs large conductance calcium-activated potassium channel activity in rat hippocampal neurons. Journal Published:

PUBLICATION TYPE: Journal Article

Journal: Free radical biology & medicine

VOLUME: 44

Page Numbers: 547-57

Journal Abbreviation: Free Radic. Biol. Med.

ISSN: 0891-5849

DAY: 22

MONTH: 10

YEAR: 2007

Nitric oxide deficit in chronic intermittent hypoxia impairs large conductance calcium-activated potassium channel activity in rat hippocampal neurons. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 8709159

Nitric oxide deficit in chronic intermittent hypoxia impairs large conductance calcium-activated potassium channel activity in rat hippocampal neurons. Keywords Mesh Terms:

KEYWORDS:

MESH TERMS:

Chemical & Substance for Abstract: Nitric oxide deficit in chronic intermittent hypoxia impairs large conductance calcium-activated potassium channel activity in rat hippocampal neurons. Information

Substance Name:

Registry Number:

Grant and Affiliation Information for Nitric oxide deficit in chronic intermittent hypoxia impairs large conductance calcium-activated potassium channel activity in rat hippocampal neurons.

AFFILIATION: Department of Physiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.

Country: United States

AGENCY:

GRANT:

ACRONYM:

MEDLINETA: Free Radic Biol Med

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

Nitric oxide deficit in chronic intermittent hypoxia impairs large conductance calcium-activated potassium channel activity in rat hippocampal neurons Related Publications

• A Semi-Automatic Clustering-Based Level Set Method for Segmentation of Endocardium from MSCT Images.
• A cross-cultural study of employers' concerns about hiring people with psychotic disorder: implications for recovery.
• Age differences in coping and emotional responses toward SARS: a longitudinal study of Hong Kong Chinese.
• An interactive lesson in acid/base and pro-drug chemistry using sodium gamma-hydroxybutyrate and commercial test coasters.
• Brain proteins interacting with the tetramerization region of non-erythroid alpha spectrin.
• Case report: denys- drash syndrome.
• Cervicovaginal fistula secondary to embedded fetal bones: a case report.
• Conflict of interest policy.
• Conflict of interest policy.
• Conformational change of erythroid alpha-spectrin at the tetramerization site upon binding beta-spectrin.
• Differential expressions and roles of hypoxia-inducible factor-1alpha, -2alpha and -3alpha in the rat carotid body during chronic and intermittent hypoxia.
• Dynamic treatment for proximal phalangeal fracture of the hand.
• Gene selection for Brain Cancer Classification.
• Inactivation of hepatic enzymes by inhalant nitrite--in vivo and in vitro studies.
• Molecular epidemiology of community-acquired methicillin-resistant Staphylococcus aureus bacteremia in a teaching hospital.
• Pheophorbide a, an active component in Scutellaria barbata, reverses P-glycoprotein-mediated multidrug resistance on a human hepatoma cell line R-HepG2.
• Posaconazole: an extended-spectrum triazole antifungal agent.
• Principles-based medical informatics for success--how Hong Kong built one of the world's largest integrated longitudinal electronic patient records.
• Quality indicators for hospitalization and surgery in vulnerable elders.
• Quality indicators for screening and prevention in vulnerable elders.
• Quality indicators for the care of hypertension in vulnerable elders.
• Quality indicators for the care of sleep disorders in vulnerable elders.
• Quality indicators for the care of stroke and atrial fibrillation in vulnerable elders.
• Real-time ultrasonic biparietal diameter measurement for the prediction of gestational age in llamas.
• Separation and determination of metal cations in milk and dairy products by CE.
• The application of thermal methods for determining chemical composition of carbonaceous aerosols: a review.
• The effect of therapeutic ultrasound intensity on the ultrastructural morphology of tendon repair.
• WAIS-III percentile scores by education and sex for U.S. and Canadian populations.
• [Analysis of causes of late mortality in liver transplant recipients]
• [Construction and characterization of the cDNA library from Schistosoma japonicum cercariae]