Moss T J, Davey M G, McCrabb G J, Harding R
Department of Physiology, Monash University, Clayton, Victoria, Australia.
J Appl Physiol (1985). 1996 Oct;81(4):1555-61. doi: 10.1152/jappl.1996.81.4.1555.
Our aim was to determine the effects of low birth weight on ventilatory responses to progressive hypoxia and hypercapnia during early postnatal life. Seven low-birth-weight (2.7 +/- 0.3 kg) and five normal-birth-weight (4.8 +/- 0.2 kg) lambs, all born at term, underwent weekly rebreathing tests during wakefulness while arterial PO2, PCO2, and pH were measured. Hypoxic ventilatory responsiveness (HOVR; percent increase in ventilation when arterial PO2 fell to 605 of resting values) increased in normal lambs from 86.6 +/- 7.1% at week 1 to 227.4 +/- 24.9% at week 6. In low-birth-weight lambs, HOVR was not significantly different at week 1 (60.1 +/- 18.7%) from that of normal lambs but did not increase with postnatal age (56.6 +/- 19.3% at week 6). HOVR of all lambs at 6 wk was significantly correlated with birth weight (r2 = 0.8). Hypercapnic ventilatory responsiveness (gradient of ventilation vs. arterial PCO2) did not change with age and was not significantly different between groups [84.7 +/- 7.5 (low-birth-weight lambs) vs. 89.4 +/- 6.6 ml.min-1.kg-1.mmHg-1 (normal lambs)]. We conclude that intrauterine conditions that impair fetal growth lead to the failure of HOVR to increase with age.
我们的目的是确定低出生体重对出生后早期通气对渐进性缺氧和高碳酸血症反应的影响。七只低出生体重（2.7±0.3千克）和五只正常出生体重（4.8±0.2千克）的羔羊，均为足月出生，在清醒状态下每周进行重复呼吸测试，同时测量动脉血氧分压（PO2）、二氧化碳分压（PCO2）和pH值。正常羔羊的低氧通气反应性（HOVR；动脉PO2降至静息值的60%时通气增加的百分比）从第1周的86.6±7.1%增加到第6周的227.4±24.9%。在低出生体重羔羊中，第1周时HOVR（60.1±18.7%）与正常羔羊无显著差异，但未随出生后年龄增加（第6周时为56.6±19.3%）。所有羔羊在6周龄时的HOVR与出生体重显著相关（r2 = 0.8）。高碳酸通气反应性（通气与动脉PCO2的梯度）不随年龄变化，两组之间无显著差异[84.7±7.5（低出生体重羔羊）对89.4±6.6毫升·分钟-1·千克-1·毫米汞柱-1（正常羔羊）]。我们得出结论，损害胎儿生长的宫内条件导致HOVR不能随年龄增加。
