Abstract
The role of nonmyelinated and myelinated vagal afferents in pulmonary reflexes and breathing pattern was examined in elastase-treated emphysemic rats. Fourteen to 17 days after intratracheal instillation of 1 IU/gm of porcine pancreatic elastase or 0.5 mL of saline, elastase-treated rats had a decreased alveolar surface area to volume of parenchyma (Sv) (42.44 ± 1.7 vs. 31.51 ± 1.1 mm2/mm3), increased quasistatic compliance (QSC) (1.05 ± 0.06 vs. 1.25 ± 0.09 mL/cm H2O), functional residual capacity (FRC) (4.31 ± 0.10 vs. 5.88 ± 0.37 mL), residual volume (RV) (3.02 ± 0.14 vs. 4.27 ± 0.31 mL), and total lung capacity (TLC) (14,04 ± 0.28 vs. 15.58 ± 0.54 mL). There were no changes in the strength of the pulmonary chemoreflex, the strength of the Hering-Breuer inflation reflex, or breathing pattern before or after vagal perineural capsaicin treatment (VPCT) or vagotomy. There were, however, significant negative correlations between Sv and TLC, FRC and RV, and a near significant (p < .09) negative correlation between Sv and QSC, but no significant correlations between Sv and indices of either the pulmonary chemoreflex or Hering-Breuer inflation reflex. The results indicate that pulmonary vagal nonmyelinated and myelinated reflex activity and breathing pattern are not affected by elastase-induced emphysema in rats.
Original language | English (US) |
---|---|
Pages (from-to) | 441-457 |
Number of pages | 17 |
Journal | Experimental Lung Research |
Volume | 23 |
Issue number | 5 |
State | Published - 1997 |
Keywords
- C-fibers
- Elastase
- Emphysema
- Rapid shallow breathing
- Vagal afferents
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine