Related Experiment Video
Updated: Jul 18, 2026

Cardiac Pressure-Volume Loop Analysis Using Conductance Catheters in Mice
Published on: September 17, 2015
Hemodynamic effects of labetalol, an alpha and beta adrenergic blocking agent, in hypertensive subjects
Abstract:
Labetalol was administered to six hypertensive subjects in increasing doses for seven days. A decrease in both supine and standing arterial pressure and heart rate was observed with no change in cardiac output and few side effects. Exercise tolerance was unaltered by the drug, but the heart rate and arterial pressure response to exercise were significantly blunted. The infusion rate of isoproterenol required to produce tachycardia was increased sevenfold by 800 mg/day labetalol and tenfold by 1600 mg/day. More than twice the control dose of phenylephrine was required during labetalol therapy to produce a rise in diastolic arterial pressure reflex tachycardia to amyl nitrite-induced hypotension was attenuated. These studies indingina pectoris.
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: Pharmacological Actions of β-Receptor Blockers
Adrenergic Antagonists: ɑ and β-Receptor Blockers
Antihypertensive Drugs: Action of β1 Blockers
Antihypertensive Drugs: Types of β-Blockers
Heart Failure Drugs: β-Blockers

