TY - JOUR
T1 - Bronchopulmonary C-fibers modulate the breathing pattern in surfactant-depleted juvenile cats
AU - Rieger-Fackeldey, Esther
AU - Sindelar, Richard
AU - Sedin, Gunnar
AU - Jonzon, Anders
N1 - Funding Information:
The authors are indebted to Barbro Kjällström for excellent laboratory assistance. This study was financially supported by grants from the Swedish Research Council (72X-04998); Her Royal Highness The Crown Princess Lovisa's Foundation for Children's Health Care, Stockholm; Habilitationsstipendium, Hochschul- und Wissenschaftsprogramm des Bundes und der Länder, Germany.
PY - 2008/2/29
Y1 - 2008/2/29
N2 - The aim of this study was to investigate the influence of nonmyelinated C-fibers on the breathing pattern by cooling the vagal nerves to temperatures at which myelinated nerve transmission from pulmonary stretch receptors is blocked (+7 °C) and further at which nonmyelinated fiber input is blocked (0 °C), in anaesthetized spontaneously breathing juvenile cats with normal (LN), surfactant-depleted (LD) and surfactant-treated (LT) lungs. In LN, vagal cooling from +7 to 0 °C decreased respiratory frequency (fR; -8%; p < 0.01), and increased tidal volume (VT; +40%; p < 0.01). In the presence of shallow fast breathing in LD, fR decreased (+38 to +7 °C: -26%; p < 0.015 and +7 to 0 °C: -24%; p < 0.001) and VT increased (+37%; p < 0.049 and +88%; p < 0.016). In LT, fR decreased (+7 to 0 °C: -21%; p < 0.001), whereas VT remained the same at 0 °C (+12%; NS). These findings show for the first time that the activity of bronchopulmonary C-fibers have a prominent role in modulating the breathing pattern in juvenile cats with surfactant-depleted lungs.
AB - The aim of this study was to investigate the influence of nonmyelinated C-fibers on the breathing pattern by cooling the vagal nerves to temperatures at which myelinated nerve transmission from pulmonary stretch receptors is blocked (+7 °C) and further at which nonmyelinated fiber input is blocked (0 °C), in anaesthetized spontaneously breathing juvenile cats with normal (LN), surfactant-depleted (LD) and surfactant-treated (LT) lungs. In LN, vagal cooling from +7 to 0 °C decreased respiratory frequency (fR; -8%; p < 0.01), and increased tidal volume (VT; +40%; p < 0.01). In the presence of shallow fast breathing in LD, fR decreased (+38 to +7 °C: -26%; p < 0.015 and +7 to 0 °C: -24%; p < 0.001) and VT increased (+37%; p < 0.049 and +88%; p < 0.016). In LT, fR decreased (+7 to 0 °C: -21%; p < 0.001), whereas VT remained the same at 0 °C (+12%; NS). These findings show for the first time that the activity of bronchopulmonary C-fibers have a prominent role in modulating the breathing pattern in juvenile cats with surfactant-depleted lungs.
KW - Control of breathing
KW - Pulmonary C-fiber
KW - Pulmonary stretch receptors
KW - Surfactant-depletion
KW - Vagal cooling
UR - http://www.scopus.com/inward/record.url?scp=44449105078&partnerID=8YFLogxK
U2 - 10.1016/j.resp.2007.10.017
DO - 10.1016/j.resp.2007.10.017
M3 - Article
C2 - 18088566
AN - SCOPUS:44449105078
SN - 1569-9048
VL - 160
SP - 341
EP - 349
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
IS - 3
ER -