Mautz W J, Bufalino C
Department of Community and Environmental Medicine, University of California, Irvine 92717.
Respir Physiol. 1989 Apr;76(1):69-77. doi: 10.1016/0034-5687(89)90018-2.
Breathing pattern (frequency and tidal volume), minute ventilation (VE), oxygen consumption (MO2), and rectal temperature (TR) were measured from rats exposed to 0.8, 0.6, 0.4, and 0.2 ppm O3 to determine the relation between breathing pattern responses to O3 and metabolic rate. In 0.8 ppm O3, rapid-shallow breathing began at 60 min exposure while VE and MO2 declined beginning at 40 min. In comparison to clean air exposed animals, rats (n = 8) during the third hour of 0.8 ppm O3 exposure had a 27% increase in frequency, 35% decline in tidal volume, 20% decrease in VE, 24% decrease in MO2, and 1.3 degrees C decrease in TR. At lower O3 concentrations, responses were diminished in magnitude, and in rats exposed to 0.2 ppm O3, only MO2 was significantly decreased, irritant-induced depression of VE did not imply a state of hypoventilation or hypoxia because ventilation equivalent for O2 (VE/MO2) did not decline during O3 exposures. Body temperature and metabolic rate depression have not been observed during the development of rapid-shallow breathing in dogs or humans exposed to these low levels of O3, and the present observations in rats may reflect a more labile thermoregulatory physiology among rodents. Ventilatory and metabolic rate depression in response to irritant inhalation can be an effective pulmonary defense in rodents and other heterothermic mammals.
对暴露于0.8、0.6、0.4和0.2 ppm臭氧的大鼠测量呼吸模式（频率和潮气量）、分钟通气量（VE）、耗氧量（MO2）和直肠温度（TR），以确定呼吸模式对臭氧的反应与代谢率之间的关系。在0.8 ppm臭氧环境中，暴露60分钟时开始出现快速浅呼吸，而VE和MO2在暴露40分钟时开始下降。与暴露于清洁空气的动物相比，在0.8 ppm臭氧暴露的第三个小时，大鼠（n = 8）的频率增加27%，潮气量下降35%，VE下降20%，MO2下降24%，TR下降1.3摄氏度。在较低的臭氧浓度下，反应程度减弱，在暴露于0.2 ppm臭氧的大鼠中，只有MO2显著下降，刺激性物质引起的VE降低并不意味着通气不足或缺氧状态，因为在臭氧暴露期间，氧通气当量（VE/MO2）并未下降。在暴露于这些低水平臭氧的狗或人类中，在快速浅呼吸发展过程中未观察到体温和代谢率降低，目前在大鼠中的观察结果可能反映出啮齿动物中更不稳定的体温调节生理状态。吸入刺激性物质引起的通气和代谢率降低可能是啮齿动物和其他变温哺乳动物一种有效的肺部防御机制。
