Inhibition of [3H]catecholamine release and Ca2+ currents by prostaglandin E2 in rabbit carotid body chemoreceptor cells
| Autor: | José R. López-López, L. Almaraz, A. Gómez-Niño, Constancio Gonzalez |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
medicine.medical_specialty
Chemoreceptor Physiology Nisoldipine chemistry.chemical_element Superior Cervical Ganglion In Vitro Techniques Calcium Dinoprostone Catecholamines GTP-Binding Proteins Internal medicine medicine Extracellular Animals Prostaglandin E2 Carotid Body Dihydropyridine 3-Pyridinecarboxylic acid 1 4-dihydro-2 6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)- Methyl ester Calcium Channel Blockers Denervation Electrophysiology Endocrinology medicine.anatomical_structure chemistry Catecholamine Dinitrophenol Biophysics Carotid body Calcium Channels Rabbits Research Article medicine.drug |
| Zdroj: | The Journal of Physiology. 476:269-277 |
| ISSN: | 0022-3751 |
| DOI: | 10.1113/jphysiol.1994.sp020129 |
| Popis: | Basal release of [3H]catecholamine ([3H]CA) from rabbit carotid bodies (CBs), previously incubated in the presence of [3H]tyrosine, was not significantly modified by prostaglandin E2 (PGE2). On the contrary, PGE2 (3-300 nM) produced a dose-dependent inhibition of the low PO2-evoked release of [3H]CA. The inhibition was greatest (55%) at a low intensity of hypoxic stimulation (incubating solution PO2 approximately 66 mmHg) and decreased with increasing intensities of hypoxia. Chronic denervation of the CB did not modify the response to PGE2. The release of [3H]CA induced by incubating the CBs in a hypercapnic-acidic solution (PCO2 approximately 132 mmHg; pH = 6.60) and by dinitrophenol (100 microM) was not significantly modified by 300 nM PGE2. PGE2 (300 nM) inhibited the release of [3H]CA elicited by incubating the CBs in a high K+ (35 mM)-containing solution. The release response elicited by high K+ (25 mM) was strongly augmented by a dihydropyridine agonist of Ca2+ channels, Bay K 8644, at a concentration of 1 microM. The Bay K 8644 effect was partly inhibited by PGE2 (300 nM). Using whole-cell recordings in freshly dispersed or short-term cultured chemoreceptor cells from adult rabbits it was found that Ca2+ currents (ICa) were reversibly inhibited by bath application of PGE2. A good parallelism exits between the dose-response curves for PGE2 inhibition of ICa in isolated chemoreceptor cells and high extracellular [K+]- or hypoxia-evoked release of [3H]CA from the whole CB.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: | OpenAIRE |
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