Vagal innervation is required for pulmonary function phenotype in Htr4-/- mice

We report here that the Htr4–/– phenotype in mouse is dependent on vagal innervation to the lung. Both ex vivo tracheal ring reactivity and in vivo flexiVent pulmonary functional analyses demonstrate that vagotomy abrogates the Htr4–/– airway hyperresponsiveness phenotype. Hyperpolarized 3He gas magnetic resonance imaging and stereological assessment of wild-type and Htr4–/– mice reveal no observable differences in lung volume, inflation characteristics, or pulmonary microarchitecture. Finally, control of breathing experiments reveal substantive differences in baseline breathing characteristics between mice with/without functional HTR4 in breathing frequency, relaxation time, flow rate, minute volume, time of inspiration and expiration and breathing pauses. These results suggest that HTR4’s role in pulmonary function likely relates to neural innervation and control of breathing.

Source: AJP: Lung Cellular and Molecular Physiology - April 1, 2017 Category: Respiratory Medicine Authors: House, J. S., Nichols, C. E., Li, H., Brandenberger, C., Virgincar, R. S., DeGraff, L. M., Driehuys, B., Zeldin, D. C., London, S. J. Tags: RESEARCH ARTICLE Source Type: research