Related Experiment Video
Updated: Oct 23, 2026

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy
Published on: February 20, 2018
Effect of alpha and beta adrenergic blockade on oxygen transport in rat skeletal muscle and brain
Abstract:
The effects of phenoxybenzamine HCl and propranolol HCl, 2 mg/kg, on tissue oxygen tension (PO2), perfusion and small vessel blood content of the cerebral cortex and biceps brachii muscle of anesthetized rats were determined. Perfusion and PO2 were measured polarographically and small vessel blood content was measured with 59Fe-siderophilin-labeled blood. Under control conditions PO2, perfusion and small vessel blood content averaged 15.1 mm Hg., 15.6 ml/min/100 g and 0.91 ml/100 g in brain and 15.6 mm Hg, 13.1 ml/min/100 g and 1.63 ml/100 g in muscle. After phenoxybenzamine adminstration, there was a significant increase in muscle perfusion (17.4%) and decrease in cortical PO2 (9.2%). No other factors changed significantly. Propranolol caused no significant changes in any of the above factors. Arteriolar resistance in skeletal muscle decreased after phenoxybenzamine. Small vessel blood content measurements (an estimate of open capillary density) indicate no effects on precapillary sphincters with either agent. Since some changes in metabolism were indicated with these agents, regional oxygen consumption was calculated from this data.
Related Concept Videos
Adrenergic Receptors: β Subtype
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors have equal affinities for...
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: Types of β-Blockers
Oxygen Transport in the Blood

