Related Experiment Video

Updated: Jul 18, 2026

Femoral Arterial and Venous Catheterization for Blood Sampling, Drug Administration and Conscious Blood Pressure and Heart Rate Measurements
09:38

Femoral Arterial and Venous Catheterization for Blood Sampling, Drug Administration and Conscious Blood Pressure and Heart Rate Measurements

Published on: January 24, 2012

Epinephrine sulfation in the forearm: arteriovenous differences in free and conjugated catecholamines

D A Joyce, L J Beilin, R Vandongen

    Life Sciences
    |November 29, 1982
    PubMed

    More Related Videos

    A Novel Method: Super-selective Adrenal Venous Sampling06:08

    A Novel Method: Super-selective Adrenal Venous Sampling

    Published on: September 15, 2017

    A Convenient Method for Extraction and Analysis with High-Pressure Liquid Chromatography of Catecholamine Neurotransmitters and Their Metabolites13:35

    A Convenient Method for Extraction and Analysis with High-Pressure Liquid Chromatography of Catecholamine Neurotransmitters and Their Metabolites

    Published on: March 1, 2018

    Related Concept Videos

    Adrenergic Neurons: Neurotransmission01:27

    Adrenergic Neurons: Neurotransmission

    Postganglionic sympathetic fibers (except those supplying the sweat glands) releasing noradrenaline or norepinephrine are called noradrenergic or adrenergic neurons. Noradrenaline, dopamine, adrenaline, or epinephrine are collectively called "catecholamines" as they contain a catechol moiety and an amine side chain. The five stages of neurotransmitter release involve their synthesis, storage, release, reuptake and metabolism.
    Synthesis: Catecholamine synthesis requires tyrosine, which is taken...
    Adrenergic Receptors: β Subtype01:26

    Adrenergic Receptors: β Subtype

    β-adrenoceptors have varied sensitivities towards adrenaline, noradrenaline, and isoprenaline. The order of agonist potency is as follows:
    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: 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: Mixed-Action Agents01:28

    Adrenergic Agonists: Mixed-Action Agents

    Mixed-action adrenergic agonists, like ephedrine and pseudoephedrine, directly and indirectly affect adrenergic receptors. These agents stimulate adrenoceptors and indirectly release stored neurotransmitters, amplifying the adrenergic response.
    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...
    Adrenergic Agonists: Chemistry and Structure-Activity Relationship01:16

    Adrenergic Agonists: Chemistry and Structure-Activity Relationship

    Adrenergic agonists' structure-activity relationship (SAR) determines their selectivity and efficacy. These agonists comprise a phenylethylamine moiety with an aromatic ring and an ethylamine side chain.
    Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
    Separation of the aromatic...
    Adrenergic Agonists: Therapeutic Uses01:30

    Adrenergic Agonists: Therapeutic Uses

    Adrenergic agonists have diverse therapeutic uses across various medical conditions and emergencies.
    Emergency and Intensive Care Unit (ICU) applications: Pressor agents increase blood pressure, heart rate, and contractility in shock and organ failure situations. Dopamine can induce vasodilation and stimulate adrenoceptors. Endogenous catecholamines are effective in treating cardiogenic shock. α2-agonists like clonidine can reverse anesthesia-induced hypertension.
    Allergies and anaphylaxis:...