Related Experiment Video
Updated: Aug 18, 2026

Single Cell Measurement of Dopamine Release with Simultaneous Voltage-clamp and Amperometry
Published on: November 21, 2012
[A case of amphetamine-induced down-regulation of beta-adrenoceptor]
1Department of Anesthesiology, Ohtawara Red Cross Hospital, Tochigi 324-0058.
Abstract:
A 29-year-old man with severe pyloric stenosis confessed that he had been a chronic amphetamine abuser just after awakening from anesthesia for partial gastrectomy. Anesthesia was maintained with thoracic epidural bupivacaine combined with continuous i.v. infusion of propofol. Decreased arterial blood pressure was observed 10 min after starting epidural anesthesia, and remained stable at 80-90 mmHg of systolic blood pressure in spite of massive fluid resuscitation in addition to repeated i.v. administration of ephedrine/methoxamine and continuous i.v. infusion of dopamine at a rate of 8 micrograms.kg-1.min-1. Finally, arterial blood pressure rose gradually after i.v. administration of methylpredonisolone 500 mg. We speculate that the down-regulation of beta-adrenoceptor induced by the sympathomimetic action of amphetamine, might be a major cause of refractory hypotension.
Related Concept Videos
Desensitization and Tachyphylaxis
Several...
Adrenergic Receptors (Adrenoceptors): Classification
α-Adrenoceptors
α-Adrenoceptors are classified into two main subtypes: α1 and α2. The α1 adrenoceptors, which are found on postsynaptic...
Adrenergic Receptors: β Subtype
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors have equal affinities for...
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...
Adrenergic Agonists: Mixed-Action Agents
Ephedrine and pseudoephedrine lack a catecholamine group, making them less susceptible to degradation by metabolic enzymes. They have increased oral bioavailability and lipophilicity, resulting in a longer duration of action. Their response is reduced by...
Drugs Affecting Neurotransmitter Release or Uptake

