Phrenic afferent stimulation by bradykinin and the distribution of the inspiratory motor drive.

摘要: Activation of thin-fiber (groups III and IV) afferents from the diaphragm using a capsaicin or ischemia increases respiratory muscle activity. To assess whether bradykinin causes similar effects, we injected boluses bradylinin into phrenic artery in situ, isolated innervated left hemi-diaphragm preparations 8 α-chloralose anesthetized, vagotomized, mechanically ventilated dogs. Inspiratory motor drive during spontaneous breathing attempts was assessed integrated EMG activity several inspiratory muscles. Fifty μg increased peak activities alae nasi to 110%, genioglossus 189%, 115% (P < 0.05) parasternal 109% 0.01) baseline 60 sec after injection. time decreased by 10% 0.01). The mean arterial blood pressure about 10 mmHg. Responses were with 10, 25 100 bradykinin. After phrenicotomy, did not affect timing. In conclusion, afferent activation exerts an excitatory but disproportion influence on drive.