Contribution of Carotid Bodies on Pulmonary Function During Normoxia and Acute Hypoxia
- 1Pontificia Universidad Catolica de Chile
- 2Institut National de la Sante et de la Recherche Medicale (Inserm)
- 3
Journal
Advances in Experimental Medicine and Biology
ISSN
0065-2598
2214-8019
Open Access
closed
Volume
1427
Start page
127
End page
134
Carotid bodies (CBs) are main peripheral chemoreceptors involved in breathing regulation. Despite the well-known role played by CBs on breathing control, the precise contribution of CBs on the regulation of lung mechanics remains controversial. Accordingly, we study changes in lung mechanics in normoxia (FiO(2) 21%) and hypoxia (FiO(2) 8%) in mice with or without functional CBs. For this, we used adult male mice that underwent sham or CB denervation (CBD) surgery. Compared to sham-operated mice, we found that CBD induced an increase in lung resistance (RL) while breathing normoxic air (sham vs. CBD, p < 0.05). Importantly, changes in R-L were accompanied by an approximately threefold reduction in dynamic compliance (Cdyn). Additionally, end-expiratory work (EEW) was increased in normoxia in the CBD group. Contrarily, we found that CBD has no effect on lung mechanics during hypoxic stimulation. Indeed, R-L, Cd-yn, and EEW values in CBD mice were undistinguishable from the ones obtained in sham mice. Finally, we found that CBD induces lung parenchyma morphological alterations characterized by reduced alveoli space. Together our results showed that CBD progressively increases lung resistance at normoxic conditions and suggest that CB tonic afferent discharges are needed for the proper regulation of lung mechanics at rest.