Javorka K, Calkovská A, Petrásková M, Gecelovská V
Department of Physiology, Faculty of Medicine, Comenius University, Martin, Slovak Republic.
Physiol Res. 1996;45(6):439-47.
The effects of different body temperature (BT) on the respiratory and cardiovascular parameters and respiratory reflexes were studied in 33 anaesthetized adult rabbits. Hyperthermia elicited panting with mean panting respiratory rate 199 +/- 14 x min-1 in all anaesthetized rabbits. Significant correlations between BT and frequency of breathing (positive), heart rate (positive) or tidal volume (negative) were found. Cooling was accompanied by considerable arterial hypotension. Duration of the Hering-Breuer reflex (HB) was reduced by the rise of BT. Intensity of the reflex (assessed as the ratio of the apnoeic pause to the mean duration of the previous 5 breaths) was unchanged up to the body temperature eliciting panting (41.15 +/- 0.08 degrees C) when it was greatly diminished. Defensive airway reflexes were also changed in hyperthermia. The duration as well as the intensity of nasal apnoea (Kratschmer's reflex) and laryngeal chemoreflex apnoea were decreased. The intensities of respiratory efforts in sneezing and laryngeal coughing were reduced. The expulsive reactions evoked by mechanical stimulation of the larynx were replaced by very shortlasting inhibition of breathing during panting. The results indicate that reflex control of breathing via the Hering-Breuer reflex and the ability to eliminate irritants from the airways are diminished during hyperthermia and panting in anaesthetized rabbits.
在33只麻醉的成年兔中研究了不同体温（BT）对呼吸、心血管参数及呼吸反射的影响。在所有麻醉兔中，体温过高引发气喘，平均气喘呼吸频率为199±14次/分钟。发现BT与呼吸频率（正相关）、心率（正相关）或潮气量（负相关）之间存在显著相关性。降温伴有明显的动脉低血压。赫林-布雷尔反射（HB）的持续时间随BT升高而缩短。反射强度（以呼吸暂停时间与前5次呼吸平均持续时间的比值评估）在引发气喘的体温（41.15±0.08℃）之前保持不变，之后大幅减弱。在体温过高时，防御性气道反射也发生改变。鼻呼吸暂停（克拉奇默反射）和喉化学反射性呼吸暂停的持续时间及强度均降低。打喷嚏和喉咳嗽时的呼吸努力强度降低。通过机械刺激喉部引发的呼气反应在气喘时被极短暂的呼吸抑制所取代。结果表明，在麻醉兔体温过高和气喘期间，通过赫林-布雷尔反射对呼吸的反射性控制以及从气道清除刺激物的能力会减弱。
