Related Experiment Video

Updated: Aug 15, 2026

Implantation of hiPSC-derived Cardiac-muscle Patches after Myocardial Injury in a Guinea Pig Model
07:03

Implantation of hiPSC-derived Cardiac-muscle Patches after Myocardial Injury in a Guinea Pig Model

Published on: March 18, 2019

Papaverine enhances the effect of adenosine in guinea-pig atria

H Moritoki, M Takei, S Fujita

    Naunyn-Schmiedeberg'S Archives of Pharmacology
    |October 1, 1984
    PubMed

    More Related Videos

    Testing Acetylcholine Followed by Adenosine for Invasive Diagnosis of Coronary Vasomotor Disorders05:58

    Testing Acetylcholine Followed by Adenosine for Invasive Diagnosis of Coronary Vasomotor Disorders

    Published on: February 3, 2021

    Sterile Pericarditis in Aachener Minipigs As a Model for Atrial Myopathy and Atrial Fibrillation08:56

    Sterile Pericarditis in Aachener Minipigs As a Model for Atrial Myopathy and Atrial Fibrillation

    Published on: September 24, 2021

    Related Concept Videos

    G-Protein Gated Ion Channels01:21

    G-Protein Gated Ion Channels

    GPCRs are primarily responsible for our sense of smell, taste, and vision.  The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
    Sensory organs,...
    Adrenergic Receptors: ɑ Subtype01:31

    Adrenergic Receptors: ɑ Subtype

    Adrenoceptors are classified into α and ꞵ classes based on their potencies to catecholamine agonists. α-adrenoceptors show the following order of catecholamine potency:
    Adrenaline ≥ Noradrenaline >> Isoprenaline
    α-adrenoceptors are further divided into α1 and α2-adrenoceptors.
    α1-Adrenoceptors: These receptors are located postsynaptically on the effector organs and cause constriction of smooth muscle mediated by activation of phospholipase C—inositol-1,4,5-trisphosphate...
    Adrenergic Agonists: Direct-Acting Agents01:30

    Adrenergic Agonists: Direct-Acting Agents

    Drugs that mimic the action of endogenous catecholamines like noradrenaline and adrenaline are called adrenergic agonists or sympathomimetics. Based on their mechanism of action, sympathomimetics can be classified as direct-, indirect-, or mixed-acting sympathomimetics. Direct-acting adrenergic agonists activate adrenoceptors without affecting presynaptic neurons, making them independent of neuronal catecholamine-depleting agents like reserpine and guanethidine.
    These agents can be classified...
    Adrenergic Agonists: Indirect-Acting Agents01:25

    Adrenergic Agonists: Indirect-Acting Agents

    Indirect-acting adrenergic agonists potentiate the effects of endogenous catecholamines through different mechanisms without directly binding to adrenoceptors.
    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...
    Drugs Affecting Neurotransmitter Release or Uptake01:21

    Drugs Affecting Neurotransmitter Release or Uptake

    Certain drugs can affect how neurotransmitters called catecholamines, are released or taken back up in the adrenergic neuron. They can have different effects on the body's sympathetic transmission. Reserpine, a natural compound found in the Rauwolfia shrub, blocks a transporter called vesicular monoamine transporter (VMAT), which leads to a buildup of catecholamines in the cell and reduces sympathetic transmission. Another drug called guanethidine works in multiple ways, including blocking...
    Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers01:24

    Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

    Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which indirectly block calcium...