Gustin P, Dhem A R, Lekeux P, Lomba F, Lándsér F J, Van de Woestijne K P
Centre de Physio-pathologie Animale, Faculté de Médecine Vétérinaire, Université de Liège, Bruxelles, Belgique.
J Vet Pharmacol Ther. 1989 Mar;12(1):58-64. doi: 10.1111/j.1365-2885.1989.tb00642.x.
The purpose of this study was to investigate the effects of some alpha and beta sympathomimetic and sympatholytic drugs on respiratory impedance in healthy conscious calves. Ten Friesian calves were investigated in this study. The forced oscillation technique was used to measure the resistance (Rrs) and the reactance (Xrs) of the respiratory system at frequencies ranging from 4 to 26 Hz. Isoprenaline (1 microgram/kg i.v.), propranolol (3 micrograms/kg i.v.), noradrenaline (2 micrograms/kg i.v.), xylazine (20 micrograms/kg i.v.) and yohimbine (0.25 mg/kg i.v.) were were administered. Isoprenaline induced a significant decrease of Rrs. An increase of Rrs after administration of propranolol was observed but without any change of the frequency dependence of Rrs. A small increase in the resonant frequency was also recorded. A decrease of Rrs was recorded after yohimbine injection. Noradrenaline and xylazine administration increased the resistances and the resonant frequency and induced a negative frequency dependence of Rrs. These results suggest that (1) the major effects of beta adrenergic drugs are on the central airways, (2) the alpha adrenergic system may play a role on the regulation of bronchomotor tone in calves, (3) the effects of alpha adrenergic drugs are on both central and peripheral airways and (4) the forced oscillation technique allows the differentiation of calibre changes occurring in small and large airways.
本研究的目的是调查一些α和β拟交感神经药及抗交感神经药对健康清醒犊牛呼吸阻抗的影响。本研究对10头弗里斯兰犊牛进行了调查。采用强迫振荡技术在4至26赫兹的频率范围内测量呼吸系统的阻力（Rrs）和电抗（Xrs）。静脉注射异丙肾上腺素（1微克/千克）、普萘洛尔（3微克/千克）、去甲肾上腺素（2微克/千克）、赛拉嗪（20微克/千克）和育亨宾（0.25毫克/千克）。异丙肾上腺素使Rrs显著降低。观察到普萘洛尔给药后Rrs增加，但Rrs的频率依赖性无任何变化。还记录到共振频率有小幅增加。育亨宾注射后记录到Rrs降低。去甲肾上腺素和赛拉嗪给药增加了阻力和共振频率，并导致Rrs出现负频率依赖性。这些结果表明：（1）β肾上腺素能药物的主要作用部位是中央气道；（2）α肾上腺素能系统可能在犊牛支气管运动张力的调节中起作用；（3）α肾上腺素能药物对中央和外周气道均有作用；（4）强迫振荡技术能够区分小气道和大气道中发生的管径变化。
