Delpierre S, Duté N, Jammes Y
Laboratoire de Physiologie Respiratoire, Faculté de Médecine Timone, Marseille, France.
Neurosci Lett. 1994 Oct 10;180(1):1-4. doi: 10.1016/0304-3940(94)90899-0.
Previous works demonstrated that the excitatory role of serotonin (5-hydroxytryptamine, 5-HT) on ventilation is mediated by 5-HT1,2 receptors stimulation. We hypothesized that load-induced hypoventilation could be minimized by a central release of 5-HT. Conversely, blockade of 5-HT receptors should accentuate hypoventilation. We compared the ventilatory effects of methysergide (MS), a 5-HT1,2 receptors antagonist, in 3 groups of anesthetized, spontaneously breathing rabbits: (1) a group of animals breathing for 60 min through a 370 cm H2O.liter-1.s inspiratory resistive load (IRL group), whose paCO2 increased with IRL; (2) a Control group; (3) a Control + CO2 group, made hypercapnic to assess the possible effect of this stimulus on the ventilatory responses to MS. In the 3 groups, i.v. injection of MS induced the same ventilatory changes, characterized by a rapid shallow breathing with a shorter integrated diaphragmatic activity. This confirms the tonic facilitatory effect of 5-HT on ventilation and suggests that IRL would not increase 5-HT release in the sites close to the respiratory nuclei.
先前的研究表明，血清素（5-羟色胺，5-HT）对通气的兴奋作用是由5-HT1、2受体的刺激介导的。我们推测，5-HT的中枢释放可以将负荷诱导的通气不足降至最低。相反，5-HT受体的阻断应该会加重通气不足。我们比较了5-HT1、2受体拮抗剂美西麦角（MS）对3组麻醉状态下自主呼吸的兔子的通气影响：（1）一组动物通过370 cm H2O·升-1·秒的吸气阻力负荷呼吸60分钟（IRL组），其动脉血二氧化碳分压（PaCO2）随吸气阻力负荷增加；（2）一个对照组；（3）一个对照+二氧化碳组，使其处于高碳酸血症状态，以评估这种刺激对MS通气反应的可能影响。在这3组中，静脉注射MS引起了相同的通气变化，其特征为快速浅呼吸，膈肌综合活动时间缩短。这证实了5-HT对通气的紧张性促进作用，并表明吸气阻力负荷不会增加呼吸核附近部位的5-HT释放。
