Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells.

Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells. Abstract Text:

V Carabelli,A Marcantoni,V Comunanza,A de Luca,J ,R Borges,E Carbone,V Carabelli,A Marcantoni,V Comunanza,A de Luca,J ,R Borges,E Carbone,

alpha(1H) T-type channels recruited by beta(1)-adrenergic stimulation in rat chromaffin cells (RCCs) are coupled to fast exocytosis with the same Ca(2+) dependence of high-threshold Ca(2+) channels. Here we show that RCCs exposed to chronic hypoxia (CH) for 12-18 h in 3% O(2) express comparable densities of functional T-type channels that depolarize the resting cells and contribute to low-voltage exocytosis. Following chronic hypoxia, most RCCs exhibited T-type Ca(2+) channels already available at -50 mV with the same gating, pharmacological and molecular features as the alpha(1H) isoform. Chronic hypoxia had no effects on cell size and high-threshold Ca(2+) current density and was mimicked by overnight incubation with the iron-chelating agent desferrioxamine (DFX), suggesting the involvement of hypoxia-inducible factors (HIFs). T-type channel recruitment occurred independently of PKA activation and the presence of extracellular Ca(2+). Hypoxia-recruited T-type channels were partially open at rest (T-type 'window-current') and contributed to raising the resting potential to more positive values. Their block by 50 microm Ni(2+) caused a 5-8 mV hyperpolarization. The secretory response associated with T-type channels could be detected following mild cell depolarizations, either by capacitance increases induced by step depolarizations or by amperometric current spikes induced by increased [KCl]. In the latter case, exocytotic bursts could be evoked even with 2-4 mm KCl and spike frequency was drastically reduced by 50 microm Ni(2+). Chronic hypoxia did not alter the shape of spikes, suggesting that hypoxia-recruited T-type channels increase the number of secreted vesicles at low voltages, without altering the mechanism of catecholamine release and the quantal content of released molecules.

Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells. Publishing Authors By Initials

V Carabelli,A Marcantoni,V Comunanza,A de Luca,J ,R Borges,E Carbone,V Carabelli,A Marcantoni,V Comunanza,A de Luca,J ,R Borges,E Carbone,

For similar abstracts research abstracts see: abstracts research

PUBMED ID PMID:

MEDLINE DATE:

Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells. Journal Published:

PUBLICATION TYPE: Research Support, Non-U.S. Gov

Journal: The Journal of physiology

VOLUME: 584

Page Numbers: 149-65

Journal Abbreviation: J. Physiol. (Lond.)

ISSN: 0022-3751

DAY: 9

MONTH: 08

YEAR: 2007

Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 266262

Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells. Keywords Mesh Terms:

KEYWORDS:

MESH TERMS:

Chemical & Substance for Abstract: Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells. Information

Substance Name:

Registry Number:

Grant and Affiliation Information for Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells.

AFFILIATION: Department of Neuroscience, NIS Center of Excellence, CNISM Research Unit, 10125 Torino, Italy.

Country: England

AGENCY:

GRANT:

ACRONYM:

MEDLINETA: J Physiol

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells Related Publications

• Algorithm to estimate the Hurst exponent of high-dimensional fractals.
• Breast cancer: changing strategy for treatment.
• Calcium channels in chromaffin cells: focus on L and T types.
• Can distance education prepare future public health nutritionists? A case study.
• Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells.
• Crocidolite asbestos and SV40 are cocarcinogens in human mesothelial cells and in causing mesothelioma in hamsters.
• Dendritic cell-induced memory T cell activation in nonlymphoid tissues.
• Distinct roles of VEGFR-1 and VEGFR-2 in the aberrant hematopoiesis associated with elevated levels of VEGF.
• Fast exocytosis mediated by T- and L-type channels in chromaffin cells: distinct voltage-dependence but similar Ca2+ -dependence.
• Fatal stroke in a young cocaine drug addict: chemical hair analysis and cervical artery examination twenty months after death.
• Host and direct antitumor effects and profound reduction in tumor metastasis with selective EP4 receptor antagonism.
• Hypoalbuminemic and hypocholesterolemic effect of L-asparaginase (NSC-109,229) treatment in man--a preliminary report.
• Immune Activation and Increased Prevalence of Thrombosis in HIV Infection.
• Immunocell-array for molecular dissection of multiple signaling pathways in mammalian cells.
• Intraortic negative pressure suction during glue application.
• Is matching innate?
• L-type calcium channels in adrenal chromaffin cells: role in pace-making and secretion.
• METHYLTESTOSTERONE, RELATED STEROIDS, AND LIVER FUNCTION.
• Mass spectrometry to classify non-small-cell lung cancer patients for clinical outcome after treatment with epidermal growth factor receptor tyrosine kinase inhibitors: a multicohort cross-institutional study.
• Ovarian endomyometrioma with atypias: description of a case.
• Phase I study of Paclitaxel given by seven-week continuous infusion concurrent with radiation therapy for locally advanced non-small cell lung cancer.
• Preliminary studies with dibromomannitol (NSC-94100) in patients with chronic myelogenous leukemia.
• Proteomics analysis in lung cancer: challenges and opportunities.
• Some observations of the behavior of amylase in relation to acute renal insufficiency.
• Spoken word frequency counts based on 1.6 million words in American English.
• The SV40 Large T Antigen-p53 Complexes Bind and Activate the Insulin-like Growth Factor-I Promoter Stimulating Cell Growth.
• The present dilemma of adjuvant chemotherapy: acceptance and risks versus benefits.
• Two-step aortic cross-clamping technique for acute type-a aortic dissection in octogenarians.
• [Chronic angioedema and blastocystis hominis infection]
• [Not Available.]