Related Experiment Video
Updated: Jun 22, 2026

Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology
Published on: August 18, 2014
[Effect of ropivacaine on neuronal norepinephrine reuptake in smooth muscle.]
Carlos Alberto de Souza Martins1, Pedro Wanderley de Aragão, Sonia Maria de Farias Freire
1Disciplina de Farmacologia, UFMA.
Background And Objectives:
In addition to local anesthetic action, ropivacaine has clinically significant vasoconstrictor effects, which may be observed at infiltrative anesthesia, making it an important anesthetic for field blockade. This study aimed at characterizing the constrictor mechanism of ropivacaine on smooth muscles.
Methods:
Norepinephrine concentration-effect curves in the absence or presence of ropivacaine were plotted on isolated preparations of vas deferens of rats. In another series of experiments rats were treated with reserpine (10 mg.kg-1, i.p.) to evaluate vas deferens reactivity to tyramine or norepinephrine, in the absence or presence of ropivacaine.
Results:
Ropivacaine 5 or 10 microg.mL-1 potentiated maximum norepinephrine effect (Emax) in 47% and 35%, respectively, while higher concentrations (50 or 100 microg.mL-1) inhibited its maximum effect. In isolated vas deferens of rats treated with reserpine, ropivacaine (10 or 20 microg.mL-1) potentiated (150% and 25%, respectively) norepinephrine-induced contractions, while higher concentrations (50 or 100 microg.mL-1) have not changed responses to norepinephrine.
Conclusions:
Ropivacaine blocks neuronal norepinephrine reuptake by sympathetic nerve terminals.
Related Concept Videos
Drugs Affecting Neurotransmitter Release or Uptake
Nondepolarizing (Competitive) Neuromuscular Blockers: Mechanism of Action
Competitive antagonists prevent acetylcholine from binding to its receptor, inhibiting membrane depolarization. Without conformational changes or intrinsic...
Adrenergic Agonists: Indirect-Acting Agents
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
Nondepolarizing (Competitive) Neuromuscular Blockers: Pharmacological Actions
Although all competitive neuromuscular blockers are designed...
Neurochemical Transmission: Sites of Drug Action
Depolarizing Blockers: Mechanism of Action
Succinylcholine is the most commonly used depolarizing blocker. Chemically, it constitutes two molecules of acetylcholine joined together by an acetate methyl group. They act on the receptors in the same way as acetylcholine. Because succinylcholine...