Search results for "339"

showing 3 items of 33 documents

D1 receptors play a major role in the dopamine modulation of mouse ileum contractility

2010

Since the role of dopamine in the bowel motility is far from being clear, our aim was to analyse pharmacologically the effects of dopamine on mouse ileum contractility. Contractile activity of mouse ileum was examined in vitro as changes in isometric tension. Dopamine caused a concentration-dependent reduction of the spontaneous contraction amplitude of ileal muscle up to their complete disappearance. SCH-23390, D1 receptor antagonist, which per se increased basal tone and amplitude of spontaneous contractions, antagonized the responses to dopamine, whilst sulpiride or domperidone, D2 receptor antagonists, were without effects. The application of both D1 and D2 antagonists had additive effe…

medicine.medical_specialtyDopamineMouse ileumD1 receptorIn Vitro TechniquesSettore BIO/09 - FisiologiaEnteric Nervous SystemPotassium channelsContractilityMicechemistry.chemical_compoundDopamine receptor D1IleumDopamineInternal medicineDopamine receptor D2medicineAnimalsPharmacologySCH-23390Dose-Response Relationship DrugReceptors Dopamine D1BenzazepinesAdenosine receptorContractile activityD2 receptorDopamine D2 Receptor AntagonistsEndocrinologychemistryDopamine receptorDopamine AntagonistsEndogenous agonistAdenylyl CyclasesMuscle Contractionmedicine.drugPharmacological Research
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Response to dopamine agonists of the rat isolated uterus.

1993

1. Quinpirole did not produce any effect in isolated uterus from oestrogenized rats even when it is contracted by KCl (37 mM). 2. Fenoldopam produced a relaxant effect on rat isolated uterus contracted by KCl which was not significantly modified by SCH 23390. 3. Reserpine decreased the effect of the lowest doses of fenoldopam. In reserpinized rats, propranolol (10(-9), 10(-8), 10(-7) M) antagonized the effect of the lowest doses of fenoldopam and neither SCH 23390, sulpiride nor ranitidine modified the effect of fenoldopam. 4. The results confirm our previous finding that DA1-receptors are not functional in our preparation. The effect of fenoldopam was partially due to a catecholamine-relea…

medicine.medical_specialtySerotoninQuinpiroleReserpineFenoldopamDopamine AgentsUterusPropranololPharmacologyFenoldopamIn Vitro TechniquesDopamine agonistchemistry.chemical_compoundUterine ContractionQuinpiroleCatecholaminesInternal medicineReceptors Adrenergic betamedicineAnimalsErgolinesRats WistarPharmacologySCH-23390ChemistryReserpineAcetylcholineRatsEndocrinologymedicine.anatomical_structureFemale2345-Tetrahydro-78-dihydroxy-1-phenyl-1H-3-benzazepineSulpiridemedicine.drugGeneral pharmacology
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D2-dopamine receptor blockade modulates temporal resolution in goldfish.

2002

A possible effect of dopamine on the temporal resolution of goldfish was investigated in a behavioral, two-alternative, forced-choice procedure. Flicker fusion frequency (FFF) was measured before and after bilateral intravitreal injections of D1- or D2-dopamine receptor (D1-/D2-R) antagonists, or after depletion of retinal dopamine by bilateral intravitreal injections of the dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA). Prior to drug injections, fish achieved FFFs of 33–39 Hz. A D1-R antagonist, SCH 23390, reduced FFF by about 12% (P > 0.1), whereas a D2 antagonist, sulpiride, reduced the relative FFF by 25% (P < 0.03). Depletion of retinal dopamine with 6-OHDA induced a gradual…

medicine.medical_specialtySerotoninTime FactorsTyrosine 3-MonooxygenasePhysiologyBiologyChoice BehaviorRetinaFlicker Fusionchemistry.chemical_compoundAdrenergic AgentsDopamineInternal medicineGoldfishmedicineNeurotoxinAnimalsOxidopamineSCH-23390Behavior AnimalAdaptation OcularReceptors Dopamine D2DopaminergicAntagonistRetinalBenzazepinesImmunohistochemistrySensory SystemsDopamine D2 Receptor AntagonistsEndocrinologychemistryDopamine receptorConditioning OperantDopamine AntagonistsSulpirideSulpiridemedicine.drugVisual neuroscience
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