Capsaicin-sensitive nerves mediate inhibitory junction potentials and dilatation in guinea-pig mesenteric artery.
Capsaicin-sensitive nerves mediate inhibitory junction potentials and dilatation in guinea-pig mesenteric artery.
复制标题
辣椒素敏感神经介导豚鼠肠系膜动脉的抑制性连接电位和扩张。
DOI：
10.1113/jphysiol.1991.sp018828
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Kreulen,DL
中科院分区：
文献类型：
--
作者：
Meehan,AG;Hottenstein,OD;Kreulen,DL
1.本研究观察了重复神经刺激对豚鼠肠系膜下动脉及其远端分支膜电位和去甲肾上腺素收缩反应的影响。2.重复刺激血管周围神经可诱发慢抑制连接电位和扩张器反应。单独神经电击可诱发兴奋性连接电位，S。3.河豚毒素(0.3微米)或低钙(0.5 mM)灌流液可使刺激诱发的兴奋性连接电位消失。4.IJP的波幅和持续时间取决于重复神经刺激的频率和持续时间。5 Hz刺激5次，S诱发出平均波幅为2 mV，平均持续时间为130min的S刺激，当连续刺激时间间隔小于4min时，波幅呈时间依赖性降低。5.去内皮后刺激诱发的IJP不受影响。此外，阿托品(1微米)、吲哚美辛(20微米)、哌唑嗪(0.5微米)、酚妥拉明(10微米)、心得安(0.5微米)或α，β-亚甲基三磷酸腺苷(0.2微米)对刺激诱发的IJP无影响。6.用30微米的金刚乙胺或0.4 mM的6-羟基多巴胺预先处理动脉，可使刺激诱发的EBP消失，但对刺激诱发的IJP无影响。7.与重复刺激神经相似，辣椒素(10微米)本身可引起肠系膜动脉膜超极化和扩张。此外，在应用辣椒素(10微米)后，刺激诱发的IJP和扩张器反应被取消。8.与静息条件下诱发的EBP相比，刺激诱导的IJP诱发的EJP波幅降低。9.这些发现表明，除了兴奋性交感神经支配外，肠系膜动脉还接受一种抑制性、辣椒素敏感的神经支配，这种神经支配可被低频重复刺激激活。
1. The present study examined the effects of repetitive nerve stimulation on membrane potential and on contractile responses to noradrenaline in the guinea‐pig inferior mesenteric artery and its distal branches. 2. Repetitive stimulation of perivascular nerves evoked slow inhibitory junction potentials (IJPs) and dilator responses. Individual nerve shocks elicited excitatory junction potentials (EJP)s. 3. Stimulation‐evoked IJPs were abolished in the presence of tetrodotoxin (0.3 microM) or a low‐Ca2+ (0.5 mM) superfusion solution. 4. The amplitudes and durations of IJPs were dependent on the frequency and duration of repetitive nerve stimulation. Nerve stimulation delivered at 5 Hz for 5 s induced IJPs which had an average amplitude of 2 mV and an average duration of 130 s. When the time interval between successive stimulation periods was less than 4 min, the amplitudes of IJPs were reduced in a time‐dependent manner. 5. Stimulation‐evoked IJPs were unaffected following endothelium removal. Furthermore, stimulation‐evoked IJPs were not affected by atropine (1 microM), indomethacin (20 microM), prazosin (0.5 microM), phentolamine (10 microM), propranolol (0.5 microM) or alpha,beta‐methylene ATP (0.2 microM). 6. Pre‐treatment of arteries with guanethidine (30 microM) or 6‐hydroxydopamine (0.4 mM) abolished stimulation‐evoked EJPs but had no effect on stimulation‐evoked IJPs. 7. In a similar manner to repetitive nerve stimulation, capsaicin (10 microM) itself induced membrane hyperpolarization and dilatation in mesenteric arteries. Moreover, following application of capsaicin (10 microM), stimulation‐evoked IJPs and dilator responses were abolished. 8. EJPs evoked during stimulation‐induced IJPs were reduced in amplitude, compared to EJPs evoked under resting conditions. 9. These findings suggest that, in addition to an excitatory sympathetic innervation, mesenteric arteries receive an inhibitory, capsaicin‐sensitive innervation which is activated by low‐frequency repetitive stimulation.