Related Experiment Video
Updated: Aug 4, 2026

Disrupting Reconsolidation of Fear Memory in Humans by a Noradrenergic β-Blocker
Published on: December 18, 2014
Modification by propranolol of cardiovascular effects of induced hypoglycaemia
Abstract:
The cardiovascular effects of hypoglycaemia, with and without beta-blockade, were compared in fourteen healthy men. Eight received insulin alone, and eight, including two of the original insulin-only group, were given propranolol and insulin. In the insulin-group the period of hypoglycaemia was associated with an increase in heart-rate and a fall in diastolic blood-pressure. In the propranolol-insulin group there was a significant fall in heart-rate in most subjects and an increase in diastolic pressure. Typical S-T/T changes occurred in the insulin-group but in none of the propranolol-insulin group. Hypertension in diabetics prone to hypoglycaemia attacks should not be treated with beta-blockers because these drugs may cause a sharp rise in blood-pressure in such patients.
Related Concept Videos
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
Heart Failure Drugs: β-Blockers
Antianginal Drugs: Nitrates and β-Blockers
Organic nitrates, such as nitroglycerin, play a pivotal role. Once metabolized, they liberate nitric oxide, a molecular marvel. Nitric oxide triggers guanylyl cyclase and augments cGMP production. This biochemical cascade orchestrates the relaxation of vascular smooth muscles, ushering in vasodilation and enhancing coronary blood flow. Administered...

