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Updated: Aug 18, 2026

Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors
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Adrenergic pharmacology in rats harboring pheochromocytoma

B B Hoffman1

  • 1Department of Medicine, Stanford University School of Medicine, Calif.

Hypertension (Dallas, Tex. : 1979)
|November 1, 1991
PubMed

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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.
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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.
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