Related Experiment Video
Updated: Aug 19, 2026

Invasive Hemodynamic Characterization of the Portal-hypertensive Syndrome in Cirrhotic Rats
Published on: August 1, 2018
Interactions between phenylephrine, clonidine and xylazine in rat and rabbit aortas
K E Atalik1, A S Sahin, N Doğan
1Department of Pharmacology, Faculty of Medicine, University of Selçuk, Konya, Turkey.
Abstract:
The interaction of the alpha 2-adrenoceptor agonists clonidine and xylazine with the alpha 1-adrenoceptors in the rat and rabbit aortas was investigated. In preparations preconstricted with phenylephrine (10(-6) M), cumulative addition of clonidine and xylazine induced concentration-related vasodilatation in the presence of the alpha 2-adrenoceptor antagonist yohimbine and the beta-blocker propranolol. Neither clonidine nor xylazine treatment inhibited 5-HT- and KCl-induced vasoconstriction. It is concluded that alpha 2-agonists have affinity for alpha 1-adrenoceptors in rat and rabbit aortas.
More Related Videos
Related Concept Videos
Adrenergic Antagonists: Chemistry and Classification of ɑ-Receptor Blockers
Nonselective α-blockers: Nonselective α-blockers contain haloalkylamine or imidazoline moieties. Phenoxybenzamine, with a haloalkylamine...
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
Antihypertensive Drugs: Vasodilators
Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
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...

