Marchal F, Bairam A, Haouzi P, Hascoet J M, Crance J P, Vert P, Lahiri S
Laboratoire de Physiologie, Faculté de Médecine de Nancy, Unité 272 INSERM, Université de Nancy, France.
Respir Physiol. 1992 Nov;90(2):173-83. doi: 10.1016/0034-5687(92)90079-c.
The effects of dopamine and of dopamine D2 receptor blocker haloperidol on the activity of carotid chemoreceptors were studied in 24 anesthetized, paralyzed and artificially ventilated newborn kittens aged 0-17 days. Single or few fiber preparations of chemoreceptors were made from one carotid sinus nerve. The responses of the chemosensory afferents to intravenous injections of dopamine (5-50 micrograms.kg-1) were studied in kittens breathing air and 8% O2 in N2. The effects of haloperidol on the chemosensory activity in air or 100% O2 and on the chemosensory response to hypoxia were studied. Dopamine inhibited the chemosensory discharge in 25/44 studies in normoxia. Of the 9 studies performed in hypoxia, dopamine was excitatory in 5 or had no effect in 4 (P < 0.05 vs normoxia). Inhibition of the chemosensory discharge was observed in 24/37 studies performed in kittens aged more than 3 days and was predominantly excitatory in 6/7 studies in kittens aged 0-3 days (P < 0.01). One minute after haloperidol, the chemosensory discharge had increased significantly in all experiments. The biphasic pattern of chemosensory response to hypoxia (Marchal et al., Respir. Physiol. 87: 183-193, 1992) was not changed by haloperidol. The steady-state chemosensory activity was significantly increased after haloperidol, respectively from 3.9 +/- 0.7 impulses.sec-1 to 9.8 +/- 1.2 impulses.sec-1 in air, and from 13.1 +/- 1.4 impulses.sec-1 to 17.8 +/- 2.4 impulses.sec-1 in hypoxia (mean +/- SEM, P < 0.03). It is concluded that the dopaminergic mechanisms are active in the carotid body of the kitten, and the observed responses to dopamine and haloperidol are qualitatively similar to those reported in the adult cat.
在24只年龄为0至17天、处于麻醉、麻痹状态并接受人工通气的新生小猫身上，研究了多巴胺及多巴胺D2受体阻滞剂氟哌啶醇对颈动脉化学感受器活性的影响。从一条颈动脉窦神经制备化学感受器的单纤维或少数纤维标本。在吸入空气和含8%氧气的氮气的小猫中，研究了化学感觉传入神经对静脉注射多巴胺（5 - 50微克·千克⁻¹）的反应。研究了氟哌啶醇对在空气或100%氧气环境下的化学感觉活性以及对低氧化学感觉反应的影响。在常氧条件下的44项研究中，多巴胺在25项研究中抑制了化学感觉放电。在低氧条件下进行的9项研究中，多巴胺在5项研究中具有兴奋性，在4项研究中无作用（与常氧相比，P < 0.05）。在年龄超过3天的小猫进行的37项研究中，有24项观察到化学感觉放电受到抑制，而在年龄为0至3天的小猫进行的7项研究中，有6项主要表现为兴奋性（P < 0.01）。注射氟哌啶醇1分钟后，在所有实验中化学感觉放电均显著增加。氟哌啶醇并未改变对低氧的化学感觉反应的双相模式（Marchal等人，《呼吸生理学》87: 183 - 193, 1992）。注射氟哌啶醇后，稳态化学感觉活性显著增加，在空气中分别从3.9 ± 0.7脉冲·秒⁻¹增加到9.8 ± 1.2脉冲·秒⁻¹，在低氧状态下从13.1 ± 1.4脉冲·秒⁻¹增加到17.8 ± 2.4脉冲·秒⁻¹（平均值 ± 标准误，P < 0.03）。结论是，多巴胺能机制在小猫的颈动脉体中起作用，并且观察到的对多巴胺和氟哌啶醇的反应在性质上与成年猫中报道的反应相似。
