Kaufman M P, Ordway G A, Longhurst J C, Mitchell J H
Am J Physiol. 1982 Sep;243(3):R383-8. doi: 10.1152/ajpregu.1982.243.3.R383.
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 reflux relaxation of tracheal smooth muscle in dogs.
尽管对刺激Ⅲ类和Ⅳ类肌肉传入神经所引发的反射性心血管和通气反应已进行了广泛研究，但对于刺激这些传入神经对气道管径的影响却知之甚少。因此，在11只水合氯醛麻醉的犬中，我们记录了气管有神经支配节段的横向平滑肌张力，同时用辣椒素和缓激肽刺激Ⅲ类和Ⅳ类肌肉传入神经。将这两种物质注入去皮后肢的动脉供血中会引起气管张力呈剂量依赖性降低，而注入股静脉则要么增加张力，要么对其无影响。将辣椒素和缓激肽注入股薄肌的动脉供血中也会降低气管张力。此外，切断坐骨神经、股薄肌神经和股神经可消除因将辣椒素和缓激肽注入后肢动脉供血而导致的气管张力降低。我们得出结论，化学刺激Ⅲ类和Ⅳ类肌肉传入神经会导致犬气管平滑肌的反射性舒张。
