Cattarossi L, Haxhiu-Poskurica B, Haxhiu M A, Litmanovitz I, Martin R J, Carlo W A
Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio, USA.
Pediatr Pulmonol. 1995 Aug;20(2):94-100. doi: 10.1002/ppul.1950200208.
Peripheral chemoreceptors may be immature in neonatal animals, exhibiting maturational changes in the perinatal period. Even though methylxanthines are respiratory stimulants, many premature neonates do not respond to them. Thus, we hypothesized that carotid body activity is necessary for aminophylline to reverse hypoxia-induced respiratory depression. We exposed 16 anesthetized newborn piglets (age 2-7 days) to hypoxia (inhalation of 12% oxygen) for 5 min. Aminophylline (15 mg/kg iv) was administered either prior to (11 piglets) or following (5 piglets) carotid body denervation (CBD). Before CBD, hypoxia elicited transient initial increases in tidal volume (from 79 +/- 4 to 99 +/- 1% of maximum, mean +/- SE), minute ventilation (from 64 +/- 5 to 93 +/- 4%), and peak phrenic electroneurogram (from 63 +/- 8 to 91 +/- 6%, all P < 0.05). This was followed by a decrease in tidal volume, minute ventilation and phrenic electroneurogram (all P < 0.05). Prior to CBD, aminophylline pretreatment prevented the decrease in all the measures of respiratory output during late hypoxia. After CBD, hypoxia induced an initial and sustained depression of ventilation (tidal volume from 100 to 33 +/- 14%; frequency from 94 +/- 4 to 42 +/- 17%; minute ventilation from 100 to 32 +/- 14%, all P < 0.05) and phrenic electroneurogram (peak phrenic from 100 to 47 +/- 18%; minute phrenic from 85 +/- 6 to 55 +/- 21%, both P < 0.05). Administration of aminophylline after CBD did not prevent the profound respiratory depression elicited by hypoxia in the chemodenervated piglets.(ABSTRACT TRUNCATED AT 250 WORDS)
外周化学感受器在新生动物中可能尚未成熟，在围产期会发生成熟变化。尽管甲基黄嘌呤是呼吸兴奋剂，但许多早产新生儿对其并无反应。因此，我们推测颈动脉体活动对于氨茶碱逆转低氧诱导的呼吸抑制是必要的。我们将16只麻醉的新生仔猪（年龄2 - 7天）暴露于低氧环境（吸入12%氧气）5分钟。在颈动脉体去神经支配（CBD）之前（11只仔猪）或之后（5只仔猪）静脉注射氨茶碱（15mg/kg）。在CBD之前，低氧引起潮气量（从最大量的79±4%增加到99±1%，平均值±标准误）、分钟通气量（从64±5%增加到93±4%）和膈神经电图峰值（从63±8%增加到91±6%，所有P<0.05）短暂的初始增加。随后潮气量、分钟通气量和膈神经电图下降（所有P<0.05）。在CBD之前，氨茶碱预处理可防止低氧后期所有呼吸输出指标的下降。CBD之后，低氧引起通气（潮气量从100%降至33±14%；频率从94±4次/分钟降至42±17次/分钟；分钟通气量从100%降至32±14%，所有P<0.05）和膈神经电图（膈神经峰值从100%降至47±18%；膈神经分钟值从85±6%降至55±21%，两者P<0.05）的初始和持续抑制。CBD后给予氨茶碱并不能防止化学去神经支配仔猪中低氧引起的严重呼吸抑制。（摘要截断于250字）
