The Effects of Bronchoconstriction and Anxiety on Lung Fuction
Open Access
- Author:
- Firely, Christopher Gerald
- Area of Honors:
- Biobehavioral Health
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Sonia Angele Cavigelli, Thesis Supervisor
Dr. Lori Anne Francis, Thesis Honors Advisor - Keywords:
- asthma
anxiety
lung function
bronchoconstriction
methacholine
house dust mite
ultrasonic vocalizations
PenH - Abstract:
- Background: The goal of this study is to examine the effects of airway inflammation and bronchoconstriction on lung function in BALB/c mice. House dust mite (HDM) and methacholine are commonly used to model specific components of asthma in mice. HDM is used to induce chronic inflammation in the lungs and methacholine is used to induce bronchoconstriction, both important components in modeling asthma. In developing an animal model to study the connection between asthma and anxiety, it is important to establish an accurate dosage compensation when administering methacholine treatments to mice that have chronic airway inflammation as a result of HDM administration. Mice with chronic airway inflammation will be more sensitive to methacholine and will therefore show higher lung reactivity to the same dose of methacholine in comparison to mice that did not receive HDM administration. It is necessary to establish the correct dosage of methacholine for both treatment groups in order to compensate for this and mimic similar levels of bronchoconstriction. In addition, this study will look at the connection between early life anxiety and lung function. Mice that show high levels of anxiety early in life could show increased sensitivity to methacholine. This study will address this possible connection in order to understand the potential importance of early life anxiety in asthmatics. Methods: Periadolescent mice (n=21) were divided into four groups: 1) Mice exposed to HDM (HDM), 2) Mice exposed to Methacholine (Meth), 3) Mice exposed to both HDM and methacholine (HDM/Meth), and 4) a control group (Con). Plethysmography was used to monitor and record lung function as PenH values. Early life anxiety was measured using ultrasonic vocalizations (USV). Results: It was shown that half a dose of methacholine for the HDM exposed mice produced similar increases in PenH values compared to mice that did not receive HDM. PenH values were significantly greater for the mice that received the methacholine treatment in comparison to those that received saline, demonstrating the significant effect of methacholine on lung function. Mice that were characterized as high USV did not have greater PenH values in response to methacholine compared to low USV mice. Conclusion: In the development of an animal model for asthma, mice pre-treated with HDM to cause lung inflammation only need a half dose of methacholine to cause lung function similar to a full dose in mice that are not pre-treated with HDM. For the USV analysis, mice that demonstrated high anxiety early in life did not respond to methacholine with greater PenH values compared to those that demonstrated low anxiety.