Related Experiment Video
Updated: Oct 6, 2026

Dry Powder and Nebulized Aerosol Inhalation of Pharmaceuticals Delivered to Mice Using a Nose-only Exposure System
Published on: April 6, 2017
Effects of non-bronchoconstrictive doses of inhaled propranolol on airway responsiveness to methacholine
A Vatrella1, R Parrella, G Pelaia
1Department of Clinical and Experimental Medicine, University of Naples Federico II, Italy.
Objectives:
The aim of this study was to evaluate the effects of non-bronchoconstrictive doses of propranolol on airway hyperresponsiveness to methacholine.
Methods:
Double increasing concentrations (from 0.03 to 64 micrograms/ml) of inhaled propranolol were administered to a study population which included ten patients with mild asthma, ten rhinitics, and ten healthy control subjects. After the baseline bronchial responses to propranolol and methacholine, expressed as the cumulative provocative dose producing a 20% fall in forced expiratory volume in 1 s (PD20FEV1), were assessed, methacholine challenge was repeated after pretreatment with non-bronchoconstrictive doses of propranolol.
Results:
The pharmacologically induced beta-blockade did not cause any effect in normal individuals, but it worsened airway responsiveness to methacholine in all asthmatics (geometric mean PD20 FEV1: 257 and 87 micrograms, respectively) and some rhinitics (geometric mean PD20 FEV1: 724 and 446 micrograms, respectively).
Conclusion:
Asthmatic patients were extremely sensitive to beta-blockers, whereas we observed a variable response to propranolol within the group of rhinitic subjects. This variability in the latter group is possibly because these individuals had different degrees of airway inflammation, increased parasympathetic activity, and beta-adrenoceptor dysfunction.
Related Concept Videos
Adrenergic Antagonists: Pharmacological Actions of β-Receptor Blockers
Antiasthma Drugs: β2-Adrenoceptor Agonists
One class of bronchodilators includes β2-adrenoceptor agonists. These agents target the β2-adrenoceptors located on bronchial smooth muscle cells. By stimulating these receptors, β2-agonists induce relaxation in these...
Antiasthma Drugs: Methylxanthines
Theophylline is thought to inhibit phosphodiesterase enzymes, increasing intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). This rise in cAMP and cGMP concentrations stimulates cardiac function,...
Antihypertensive Drugs: Types of β-Blockers
Adrenergic Agonists: Mixed-Action Agents
Ephedrine and pseudoephedrine lack a catecholamine group, making them less susceptible to degradation by metabolic enzymes. They have increased oral bioavailability and lipophilicity, resulting in a longer duration of action. Their response is reduced by...
Antiasthma Drugs: Muscarinic Receptor Antagonists
Antimuscarinic agents compete with ACh for the same binding site on the muscarinic receptors. By binding to these receptors, they inhibit the downstream effects of ACh and block the parasympathetic...

