0000000000344206

AUTHOR

Rikuo Ochi

showing 3 related works from this author

L-type calcium channel activity in human atrial myocytes as influenced by 5-HT.

1993

5-Hydroxytryptamine (10 mumol/l; 5-HT) exerted a positive inotropic effect associated with an increase in the Ca2+ current (ICa) in the human right atrium. For detailed analysis, L-type Ca2+ channel currents were recorded from cell-attached patches using 100 mmol/l Ba2+ as charge carrier. Ca2+ channel activity was identified, first, by burst-like inwardly directed currents and, second, by the appearance of long channel openings promoted by Bay K 8644 (1 mumol/l) upon repetitive depolarizations from -80 to 0 mV. The unitary conductance of the Ca2+ channel amounted to 25.8 pS. During superfusion with 5-HT, ensemble averaged (mean) current was enhanced by about 60%. The increase in mean curren…

MaleSerotoninchemistry.chemical_elementAction PotentialsGatingCalciumIn Vitro TechniquesMoleCyclic AMPHumansL-type calcium channelPhosphorylation5-HT receptorAgedPharmacologyMyocardiumIsoproterenolInfantDepolarizationHeartGeneral MedicineAnatomy3-Pyridinecarboxylic acid 14-dihydro-26-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)- Methyl esterMiddle AgedMyocardial ContractionElectrophysiologyElectrophysiologyKineticschemistryChild PreschoolBiophysicsFemaleCalcium ChannelsIon Channel GatingCommunication channelNaunyn-Schmiedeberg's archives of pharmacology
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Involvement of K+ channels in the relaxant effects of YC-1 in vascular smooth muscle

1999

This study addresses the question whether K(+) channels are involved in the vasorelaxant effects of 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl-indazole (YC-1 ). In rat aorta, guinea pig aorta, and guinea pig a. carotis, YC-1 inhibited contractions induced by phenylephrine (3 microM) more potently than those induced by K(+)(48 mM). In rat aorta, tetraethylammonium (10 mM), charybdotoxin (0.2 microM), and iberiotoxin (0.1 microM), but not glibenclamide (10 microM), attenuated the relaxant effects of YC-1. In guinea pig a. carotis, YC-1 (30 microM) induced a hyperpolarisation which was antagonised by 1H-[1,2,4]oxadiazolo[4, 3-a]quinoxalin-1-one (ODQ; 50 microM). In rat aorta, YC-1 (30 microM) incr…

MaleIndazolesPotassium ChannelsTime FactorsVascular smooth muscleCharybdotoxinMuscle RelaxationGuinea PigsAorta ThoracicIn Vitro TechniquesPharmacologyMuscle Smooth VascularMembrane PotentialsRats Sprague-DawleyGlibenclamidePhenylephrinechemistry.chemical_compoundmedicine.arterymedicineAnimalsDrug InteractionsPhenylephrinePharmacologyAortaTetraethylammoniumDose-Response Relationship DrugChemistryAnatomyIberiotoxinRatsVasodilationCarotid ArteriesPotassiumFemaleZaprinastmedicine.drugEuropean Journal of Pharmacology
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Adrenoceptor-mediated effects on calcium channel currents are antagonized by 5?-(N-ethyl)-carboxamido-adenosine in guinea-pig atrial cells

1992

In guinea-pig atrial myocytes, the effects of the adenosine analogue 5′-(N-ethyl)-carboxamido-adenosine (NECA) in the presence of isoprenaline (ISO) on Ca2+ channel activity were analyzed. Single Ca2+ channel currents were recorded from cell-attached patches by application of several hundred 100 ms depolarizing steps. Under control conditions, burstlike activity of channel openings during some depolarizing steps were followed by variably long periods of quiescence (blank sweeps). During superfusion with ISO (100 nmol/l), ensemble-averaged (mean) current was increased by about 150%. The underlying mechanism was found to be a significant increase in the channel availability, defined as the ra…

medicine.medical_specialtyAdenosineGuinea Pigschemistry.chemical_elementStimulationAdenosine-5'-(N-ethylcarboxamide)In Vitro TechniquesCalciumInternal medicineIsoprenalinemedicineAnimalsHeart AtriaPharmacologyChemistryCalcium channelPurinergic receptorIsoproterenolDepolarizationGeneral MedicineAdenosine receptorAdenosineReceptors AdrenergicPerfusionEndocrinologyCalcium Channelsmedicine.drugNaunyn-Schmiedeberg's Archives of Pharmacology
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