Carotid sinus nerve is involved in cardiorespiratory responses to intracarotid injection of capsaicin in the rat.
Carotid sinus nerve is involved in cardiorespiratory responses to intracarotid injection of capsaicin in the rat.
复制标题
颈动脉窦神经参与大鼠颈动脉内注射辣椒素的心肺反应。
DOI：
10.1152/japplphysiol.00302.2005
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Zhang,Cancan
中科院分区：
文献类型：
--
作者：
Wang,Rurong;Xu,Fadi;Zhuang,Jianguo;Zhang,Cancan
The carotid sinus nerve (CSN), important in cardiorespiratory modulation, mainly contains C fibers (CSCFs). Previous studies have demonstrated that selective stimulation of bronchopulmonary C fibers (PCFs) via right atrial injection of capsaicin (Cap; ∼0.25 μg) results in an apnea (∼3 s) associated with hypotension and bradycardia. The present study was undertaken to determine the effects of activating CSCFs on cardiorespiratory activities. Intracarotid injection of Cap was performed before and after bilateral transection of the CSN in anesthetized and spontaneously breathing rats. Our results showed that1) low doses of Cap (up to 2 ng) produced an increase in minute ventilation by elevating both tidal volume and respiratory frequency with the threshold dosage at 1.0 ng (P< 0.05);2) high doses (4–64 ng) generated an apnea (prolongation of expiratory duration by ∼8-fold) and hypertension (P< 0.05);3) bilateral transection of the CSN reduced excitatory and inhibitory respiratory responses by 30 and 81%, respectively, and increased the hypertension by 88% (P< 0.05); and4) the same doses of Cap delivered into the right atrium to stimulate PCFs failed to evoke detectable cardiorespiratory responses. Our results suggest that compared with PCFs, CSCFs are more sensitive to Cap stimulation and that activation of these fibers significantly modulates cardiorespiratory activity in anesthetized rats.
