Related Experiment Video
Updated: Aug 4, 2026

Assessing Murine Resistance Artery Function Using Pressure Myography
Published on: June 7, 2013
Dogfish pressor response to potassium blocked by magnesium and phentolamine
Abstract:
In vivo infusion of MgCl2 blocks the dogfish pressor response to K+. This action of Mg2+ was contrasted to phentolamine in in vivo and in vitro experiments. Mg2+ blocks the spontaneous release of catecholamines from dogfish chromaffin tissue but does not alter the norepinephrine-induced contraction of the isolated dogfish artery. In vivo infusion of Mg2+ causes a significant decrease in resting catecholamine levels and diminishes the catecholamine release caused by K+ challenge. Both Mg2+ and phentolamine block the pressor action of K+, Mg2+ by preventing the K+-induced release of catecholamines and phentolamine by preventing the circulating catecholamines from interacting with alpha-adrenergic receptor sites.
More Related Videos
09:05Measurement of Smooth Muscle Function in the Isolated Tissue Bath-applications to Pharmacology Research
Published on: January 19, 2015
08:41Assessment of Vascular Tone Responsiveness using Isolated Mesenteric Arteries with a Focus on Modulation by Perivascular Adipose Tissues
Published on: June 3, 2019
Related Concept Videos
Nondepolarizing (Competitive) Neuromuscular Blockers: Pharmacological Actions
Although all competitive neuromuscular blockers are designed...
Antihypertensive Drugs: Action of Calcium Channel Blockers
Antihypertensive Drugs: Vasodilators
Heart Failure Drugs: Diuretics
Antianginal Drugs: Calcium Channel Blockers and Ranolazine
CCBs, a diverse class that includes dihydropyridines (nifedipine) and diphenylalkylamines (verapamil and diltiazem), exert their effect by blocking calcium channels in cardiac and smooth muscle cells. This...
Pharmacodynamic Responses: Different Types