TY - JOUR
T1 - Reflex relaxation of tracheal smooth muscle by thin-fiber muscle afferents in dogs
AU - Kaufman, M. P.
AU - Ordway, G. A.
AU - Longhurst, J. C.
AU - Mitchell, J. H.
PY - 1982
Y1 - 1982
N2 - Although the reflex cardiovascular and ventilatory responses evoked by stimulation of groups III and IV muscle afferents have been extensively investigated, less is known about the effects of stimulation of these afferents on airway caliber. Therefore, in 11 chloralose-anesthetized dogs, we recorded transverse smooth muscle tension from an innervated segment of the trachea, while we stimulated groups III and IV muscle afferents with capsaicin and bradykinin. Injection of both substances into the arterial supply of the skinned hindlimb evoked dose-dependent decreases in tracheal tension, whereas injection into the femoral vein either increased tension or had no effect on it. Injection of capsaicin and bradykinin into the arterial supply of the gracilis muscle also decreased tracheal tension. In addition, cutting the sciatic, gracilis, and femoral nerves abolished the decreases in tracheal tension caused by injection of capsaicin and bradykinin into the arterial supply of the hindlimb. We conclude that chemical stimulation of groups III and IV muscle afferents causes reflex relaxation of tracheal smooth muscle in dogs.
AB - Although the reflex cardiovascular and ventilatory responses evoked by stimulation of groups III and IV muscle afferents have been extensively investigated, less is known about the effects of stimulation of these afferents on airway caliber. Therefore, in 11 chloralose-anesthetized dogs, we recorded transverse smooth muscle tension from an innervated segment of the trachea, while we stimulated groups III and IV muscle afferents with capsaicin and bradykinin. Injection of both substances into the arterial supply of the skinned hindlimb evoked dose-dependent decreases in tracheal tension, whereas injection into the femoral vein either increased tension or had no effect on it. Injection of capsaicin and bradykinin into the arterial supply of the gracilis muscle also decreased tracheal tension. In addition, cutting the sciatic, gracilis, and femoral nerves abolished the decreases in tracheal tension caused by injection of capsaicin and bradykinin into the arterial supply of the hindlimb. We conclude that chemical stimulation of groups III and IV muscle afferents causes reflex relaxation of tracheal smooth muscle in dogs.
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U2 - 10.1152/ajpregu.1982.243.3.r383
DO - 10.1152/ajpregu.1982.243.3.r383
M3 - Article
C2 - 7114294
AN - SCOPUS:0020183723
SN - 0363-6119
VL - 12
SP - R383-R388
JO - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
JF - American Journal of Physiology - Regulatory Integrative and Comparative Physiology
IS - 2
ER -