Functional and pathphysiological study in serotonin-containing chemorecptor cells

5-羟色胺（5-HT）的化学感受器细胞的特点是使用全细胞膜片钳技术。(1)从鸡胸主动脉分离的含5-HT的化学感受器细胞具有电压门控性Na ^+通道、L型和N型Ca ^<2 +>通道以及包括氧敏感性K ^+通道在内的K ^+通道。(2)α-银环蛇毒素敏感和不敏感的烟碱型ACh受体存在于这些细胞中。(3)虽然我们试图从豚鼠和大鼠肠粘膜中分离出含有5-HT的上皮细胞（中性红阳性细胞），但在电压钳条件下，我们不能获得对电压脉冲有反应的细胞。(4)过量的KCl和藜芦碱可引起鸡胸主动脉5-HT的释放，这种释放可被Ca ^2+通道拮抗剂所抑制。ACh、烟碱和DMPP也能诱发5-HT的产生，α-银环蛇毒素可部分抑制ACh、烟碱和DMPP诱发的5-HT的产生。(5)对氯苯丙胺（PCA）诱发主动脉组织5-HT输出的时间和浓度依赖性。5-HT再摄取抑制剂，流感 关于我们 伏沙明、氟西汀和氯丙咪嗪（CLO）可引起孵育液中5-HT的剂量依赖性增加，这些药物对细胞外Ca ^2+去除不敏感。(6)CLO和PCA引起温度依赖性5-HT输出。细胞外Na ^+清除可抑制CLO诱导的5-HT分泌，但对PCA诱导的5-HT分泌无影响。(7)5-HT引起大鼠基底动脉张力和细胞内Ca ^2+浓度（[Ca ^2 +] i）的振荡性变化。在离体大鼠基底动脉血管平滑肌细胞中，UTP引起所有细胞[Ca ^<2 +>] i增加，而5-HT几乎不引起这种反应。(8)在PC12细胞，囊泡胺摄取抑制剂，利血平，减少多巴胺的含量，但不ATP的分泌囊泡。一种囊泡H ^+泵ATP酶抑制剂，巴非霉素A1，降低了这两种含量。(9)在肾上腺嗜铬细胞中，毒蕈碱和咖啡因都能引起Ca ^2+激活的K ^+电流，并伴随着[Ca ^2 +] i的增加，但咖啡因更能有效地诱发K ^+电流，即使两种药物引起的[Ca ^2 +] i增加程度相同。阿片激动剂通过G蛋白抑制电压门控Ca ^2+通道。少

Serotonin (5-HT) -containing chemoreceptor cells were characterized using a whole-cell patch clamp technique. (1) 5-HT-containing chemoreceptor cells isolated from chicken thoracic aorta have voltage-gated Na^+ channels, L- and N-type Ca^<2+> channels and K^+ channels including oxygen-sensitive K^+ channels. (2) α-Bungarotoxin-sensitive and insensitive nicotinic ACh receptors were present in these cells. (3) Although we tried to isolate epitherial cells containing 5-HT (neutral red-positive cells) from the guinea-pig and rat intestinal mucosae, we could not obtain the cells responding to voltage-pulses under the voltage-clamp condition. (4) Excess KCl and veratridine evoked 5-HT output from the chicken thoracic aorta, which was inhibited by Ca^<2+> channel antagonists. ACh, nicotine and DMPP also evoked 5-HT output partly inhibited by α-bungarotoxin. (5) p-Chloroamphetamine (PCA) evoked time- and concentration-dependent 5-HT output from the aortic tissues. 5-HT reuptake inhibitors, flu … More voxamine, fluoxetine and clomipramine(CLO) caused a dose-dependent increase in 5-HT in the incubation medium, which were insensitive to extracellular Ca^<2+> removal. (6) CLO and PCA caused a temperature-dependent 5-HT output. CLO-induced 5-HT output was inhibited by extracellular Na^+ removal but not PCA-induced one. (7) 5-HT evoked oscillatory changes in tension and intracellular Ca^<2+> concentration ([Ca^<2+>]i) in the rat basilar artery. In vascular smooth muscles cells isolated from the rat basilar artery, UTP elicited increases in [Ca^<2+>]i in all cells examined, but 5-HT hardly evoked the response. (8) In PC12 cells, a vesicular amine uptake inhibitor, reserpine, decreased the content of dopamine but not ATP in the secretory vesicles. A vesicular H^+-pump ATPase inhibitor, bafilomycine A1, decreased both contents. (9) In adrenal chromaffin cells, both muscarine and caffeine elicited Ca^<2+>-activated K^+ currents concomitant with increases in [Ca^<2+>]i, but caffeine was more effective in eleciting K^+ currents even when both drugs evoked the increase of [Ca^<2+>]i to the same extent. Opioid agonists inhibited voltage-gated Ca^<2+> channels through G proteins. Less