Katherine Lortie

Institut universitaire de cardiologie et de pneumologie de Québec | IUCPQ · Pneumology

Force adaptation of airway smooth muscle (ASM) is a process whereby the presence of tone (i.e., a sustained contraction) increases the contractile capacity. For example, tone has been shown to increase airway responsiveness in both healthy mice and humans. The goal of the present study is to elucidate the underlying molecular mechanisms. The maxima...

Air volume changes created by a conscious subject breathing spontaneously within a body box are at the basis of plethysmography, a technique used to non-invasively assess some features of the respiratory function in humans as well as in laboratory animals. The present article focuses on the application of the double-chamber plethysmography (DCP) in...

It is suggested that the frequent strain the airways undergo in asthma, due to repeated airway smooth muscle (ASM)-mediated constrictions, contributes to airway wall remodeling. However, the effects of repeated constrictions on airway remodeling, as well as the ensuing impact of this presumptive remodeling on respiratory mechanics, have never been...

Rationale: Airway hyperresponsiveness (AHR), a major hallmark of asthma, results from alterations of contractile and non-contractile elements of airway reactivity. CD34 is a sialomucin expressed on various cells involved in asthma, such as eosinophils and airway smooth muscle (ASM) precursors, highlighting its potential influence in AHR. Objectiv...

Study of Force adpatation in young healthy humans

Results about molecular mechanisms involved in Force Adaptation

The factors altering the bronchodilatory response to a deep inspiration (DI) in asthma are important to decipher. In this in vitro study, we investigated the effect of changing the duration between DIs on the rate of force recovery post-DI in guinea pig bronchi. The airway smooth muscle (ASM) within the main bronchi were submitted to length oscilla...

Force adaptation, a process whereby sustained spasmogenic activation (viz., tone) of airway smooth muscle (ASM) increases its contractile capacity, has been reported in isolated ASM tissues in vitro, as well as in mice in vivo. The objective of the present study was to assess the effect of tone on airway responsiveness in humans. Ten healthy volunt...