- 作者: Kun-Ze Lee I-Jung Lu Li-Chi Ku Jin-Tun Lin Ji-Chuu Hwang
- 作者服務機構: Department of Life Science, National Taiwan Normal University, Taipei, Taiwan, ROC
- 中文摘要: --
- 英文摘要: This study was designed to examine respiratory-relatedhypoglossal nerve activity in response to activation ofpulmonary C-fibers by capsaicin.Rats were anesthe-tized with urethane(1.2 g/kg,i.p.).Tracheostomy wasperformed.Catheters were introduced into the femo-ral vein and artery. Another catheter was placed nearthe entrance of the right atrium via the right jugularvein.Rats were paralyzed with gallamine triethiodide(5 mg/kg,i.v.),and ventilated artificially. Activities of thephrenic nerve(PNA) and the hypoglossal nerve(HNA)were recorded simultaneously. Varied doses of capsai-cin (0.625, 1.25, and 5 μg/kg)were delivered into theright atrium to activate pulmonary C-fibers. Before bi-lateral vagotomy, apnea,decreases in PNA and HNAwere observed in response to pulmonary C-fiber activa-tion by the low and moderate doses of capsaicin.Thehigh dose of capsaicin evoked an increase in PNA, animmediate tonic discharge of the hypoglossal nerve,and a decrease in phasic HNA. The onset time of HNApreceding PNA was abolished and replaced by a timelagged pattern as pulmonary C-fibers were activated.Raising COZ concentration did not attenuate the inhibi-tory effect of pulmonary C-fiber activation upon PNAand HNA. After bilateral sectioning of the vagi,adminis-tration of the moderate dose of capsaicin to activatenon-vagal C-fibers produced increases in PNA andHNA. These results suggest that pulmonary vagal C-fiber activation may narrow the diameter at the oropha-ryngeal level by a decrease in phasic HNA, which maybe disadvantageous for the maintenance of a patentupper airway.
- 中文關鍵字: --
- 英文關鍵字: Hypoglossal nerve. Phrenic nerve. Pulmonary C-fibers. Vagotomy. Hypercapnia. Rat