Segal B S, Inman J D, Moss I R
Department of Pediatrics, University of Texas, Southwestern Medical Center, Dallas 75235-9063.
Pediatr Pulmonol. 1991;11(2):113-9. doi: 10.1002/ppul.1950110207.
Resting respiratory and cardiovascular functions and the response to CO2 rebreathing were compared between 2.5 +/- 0.7 (mean +/- SE) and 34.1 +/- 1.9 day old piglets, before and after the opioid antagonist naltrexone (1 mg/kg IV). At rest, tidal volume, both absolute and per m2, inspiratory and expiratory time, absolute minute ventilation, and mean arterial pressure increased with age, and breathing frequency, minute ventilation per m2, and heart rate decreased, all of these with as well as without naltrexone. During hypercapnia, the pattern, but not the quantitative aspects of breathing changed with age. At rest, naltrexone produced hyperventilation in the young, but not in the older group. During hypercapnia, naltrexone had a sparse effect in both ages. We conclude that, in the anesthetized piglet, ventilatory functions at rest undergo change with postnatal age, but breathing responses to hypercapnia exhibit maturation in pattern only and not in magnitude. Whereas resting ventilation of young piglets is modulated by endogenous opioids, hypercapnia may activate opioids to a limited extent and in a manner unrelated to age.
在给予阿片类拮抗剂纳曲酮（1mg/kg静脉注射）前后，对2.5±0.7（均值±标准误）日龄和34.1±1.9日龄的仔猪的静息呼吸和心血管功能以及对二氧化碳再呼吸的反应进行了比较。静息时，潮气量（绝对值和每平方米的潮气量）、吸气和呼气时间、绝对分钟通气量和平均动脉压随年龄增加，而呼吸频率、每平方米分钟通气量和心率降低，无论给予纳曲酮与否均如此。在高碳酸血症期间，呼吸模式随年龄变化，但呼吸的定量方面没有变化。静息时，纳曲酮在幼龄组引起通气过度，但在老龄组则不然。在高碳酸血症期间，纳曲酮在两个年龄组的作用都很微弱。我们得出结论，在麻醉的仔猪中，静息时的通气功能随出生后年龄而变化，但对高碳酸血症的呼吸反应仅在模式上表现出成熟，而非在幅度上。幼龄仔猪的静息通气受内源性阿片类物质调节，而高碳酸血症可能在有限程度上以与年龄无关的方式激活阿片类物质。
