The Hering-Breuer reflexes in the bronchial asthma attack

Area of Science:

• Respiratory Physiology
• Pulmonary Medicine
• Asthma Pathophysiology

Background:

• The Hering-Breuer reflexes normally regulate breathing patterns, involving pulmonary stretch receptor activity.
• These reflexes influence the inspiration-expiration duration quotient and respiratory frequency.
• Their role in asthma pathophysiology requires further elucidation.

Purpose of the Study:

• To investigate the Hering-Breuer reflexes during induced bronchial asthma attacks in guinea pigs.
• To determine how pulmonary stretch receptor activity changes and affects breathing regulation during asthma.
• To explore the mechanisms behind altered respiratory control in asthma.

Main Methods:

• Establishing Hering-Breuer reflexes in guinea pigs.
• Inducing bronchial asthma attacks in the study subjects.
• Measuring pulmonary stretch receptor activity and respiratory parameters (frequency, duration quotient).

Main Results:

• Hering-Breuer reflexes regulating spontaneous breathing were found to be non-prevailing after asthma induction.
• Increased pulmonary stretch receptor activity due to lung inflation did not inhibit inspiratory activity.
• Instead, increased stretch receptor activity enhanced asthmatic tachypnea, potentially via the lung deflation reflex.

Conclusions:

• Asthma attacks disrupt normal breathing self-regulation mediated by Hering-Breuer reflexes.
• The lung inflation reflex is impaired, while the lung deflation reflex may be enhanced during asthma.
• Altered lung mechanics and uneven ventilation during asthma contribute to the excitation of lung deflation endings, exacerbating tachypnea.