Related Experiment Video
Updated: Aug 11, 2026

Cardiac Pressure-Volume Loop Analysis Using Conductance Catheters in Mice
Published on: September 17, 2015
Assessment of alpha- and beta-adrenoceptor blocking actions of labetalol
Abstract:
Isoprenaline dose-response curves plotting increases in heart rate before and after labetalol are suggestive of competitive antagonism at beta-adrenoceptor sites. Phenylephrine dose-response curves using increases in systolic pressure before and after labetalol are suggestive of competitive antagonism at alpha-adrenoceptor sites. The ratio of alpha:beta-adrenoceptor antagonism induced by labetalol is approximately 1:3. Peak pharmacological responses after a single oral dose of labetalol (400 mg) occurred between 90-120 min after administration.
More Related Videos
Related Concept Videos
Adrenergic Antagonists: Pharmacological Actions of ɑ-Receptor Blockers
α1-blockers: These drugs inhibit α1-adrenoceptors on smooth muscle cells, resulting in vasodilation. This vasodilation lowers blood pressure, making α1-blockers valuable in treating hypertension. Additionally, α1-blockers effectively address urinary obstruction...
Adrenergic Antagonists: Chemistry and Classification of β-Receptor Blockers
Adrenergic Antagonists: Pharmacological Actions of β-Receptor Blockers
Adrenergic Antagonists: ɑ and β-Receptor Blockers
Antihypertensive Drugs: Types of β-Blockers
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

