Sympathetic regulation of vascular tone via noradrenaline and serotonin in the rat carotid body as revealed by intracellular calcium imaging
Sympathetic regulation of vascular tone via noradrenaline and serotonin in the rat carotid body as revealed by intracellular calcium imaging
复制标题
细胞内钙成像揭示大鼠颈动脉体中去甲肾上腺素和血清素对血管张力的交感调节
DOI：
10.1016/j.brainres.2014.11.037
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发表时间：
2015
期刊：
影响因子：
2.9
通讯作者：
Yoshio Yamamoto
中科院分区：
文献类型：
--
作者：
Takuya Yokoyama;Nobuaki Nakamuta;Tatsumi Kusakabe;Yoshio Yamamoto
缺氧诱导的化学感受活动在颈动脉体（CB）可能是增强的交感神经调节血管紧张度在CB。在本研究中，我们记录了大鼠颈交感神经活动暴露于缺氧，并检查去甲肾上腺素（NA）和5-羟色胺（5-HT）诱导的细胞内Ca 2+（[Ca 2 +]i）的平滑肌细胞和周细胞在离体血管从CB的反应。从颈交感神经干记录的多纤维电活动在吸入低氧气体期间增加。NA引起平滑肌细胞[Ca ~（2+）] i升高，而5-HT不引起[Ca ~（2+）] i升高。NA不引起毛细血管周细胞[Ca ~（2+）] i升高，而5-HT则引起[Ca ~（2+）] i升高，这种作用可被5-HT_2受体拮抗剂酮色林抑制。总之，颈交感神经增强缺氧可能会减少血流量在CB，以增加化疗敏感性。因此，CB中的低氧化学敏感性可能涉及通过交感神经的正反馈机制。
Hypoxia-induced chemosensory activity in the carotid body (CB) may be enhanced by the sympathetic regulation of vascular tone in the CB. In the present study, we recorded cervical sympathetic nerve activity in rats exposed to hypoxia, and examined noradrenaline (NA)- and serotonin (5-HT)-induced intracellular Ca2+([Ca2+]i) responses in smooth muscle cells and pericytes in isolated blood vessels from the CB. Multifiber electrical activity recorded from the cervical sympathetic trunk was increased during the inhalation of hypoxic gas. NA induced [Ca2+]iincreases in smooth muscle cells in arteriole specimens, whereas 5-HT did not cause any [Ca2+]iresponses. However, NA did not induce [Ca2+]iincreases in pericytes in capillaries, whereas 5-HT did and this response was inhibited by the 5-HT2receptor antagonist, ketanserin. In conclusion, cervical sympathetic nerves enhanced by hypoxia may reduce blood flow in the CB in order to increase chemosensitivity. Thus, hypoxic chemosensitivity in the CB may involve a positive feedback mechanism via sympathetic nerves.