Methacholine, Long-acting M-cholinolytic and beta2-agonist on the Activity of Beta-receptors in Healthy Volunteers

Effect of Methacholine, Long-acting M-cholinolytic and beta2-agonist on the Binding Activity of Beta-receptors in Healthy Volunteers

Interventional open-labeled study in parallel groups is aimed to evaluate changes of beta receptors in healthy volunteers under the influence of inhaled metacholine, long-acting anticholinergics and beta-agonists using modified radioligand method.

Long-acting beta2-agonists and anticholinergics are main drugs in therapy of chronic obstructive pulmonary disease . Beta-agonists exert their bronchodilatory effects via β2 adrenoceptors located on airway smooth muscle cells. Anticholinergics block mainly M3-cholinoreceptors located in the airways, thus inhibiting bronchoconstriction. Metacholine blocks M2-cholinoreceptors thus inducing bronchoconstriction. It is known, that muscarine and beta-receptors interact with each other, but the detailed mechanism is unknown. For evaluating the binding activity of beta-receptors after inhalation of these drugs the modified radioligand method was used.

Inclusion Criteria:

1 Provision of signed and dated informed consent form 2. Healthy male or female, aged 18-60 years

Exclusion Criteria:

• Participants unable to perform spirometry
• Exacerbation respiratory infection within the previous four weeks
• Hypersensitivity or allergy to formoterol, metacholine or tiotropium bromide
• Females who are currently pregnant and lactating
• major surgery in the last 6 months
• Refusal to participate
• Currently participating in another clinical study