Pinkerton Kent E, Joad Jesse P
Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, CA, USA.
Clin Exp Pharmacol Physiol. 2006 Mar;33(3):269-72. doi: 10.1111/j.1440-1681.2006.04357.x.
The respiratory system is a highly ordered structure composed of over 40 cell types involved in a multitude of functions. Development of the lungs spans from embryogenesis to adult life, passing through several distinct stages of growth. 2. Oxidant gases, airborne particles and environmental tobacco smoke are common air pollutants that could have a significant impact on the lungs during both pre- and postnatal periods of life. Although the specific target cells for exposure to these pollutants are not clearly identified, these cells are likely to affect critical signals or mediators expressed during distinct stages of lung development. 3. Neonatal susceptibility to environmental pollutants may be caused by either direct or indirect hits on several cell types to influence cell differentiation, proliferation and/or maturation. Air pollutants may also alter the normal developmental pattern for metabolic, immune and neurological functions that are constantly changing during in utero and postnatal growth. 4. The sensitivity of neonatal cells to environmental insults is likely to be completely different from these same cell types found in the adult. Delivery of an environmental toxicant to the respiratory system is also dramatically different during the fetal compared with the postnatal period. Passage and interaction of environmental factors through other organ systems and the vasculature, as well as maternal influences, must be taken into consideration when evaluating the impact of an environmental toxicant during early life. 5. To understand the heath outcomes of exposure to a variety of environmental factors in the respiratory system of children requires careful consideration that lung development is a multistep process and cannot be based on studies in adults.
呼吸系统是一个高度有序的结构，由40多种参与多种功能的细胞类型组成。肺的发育从胚胎发生到成年期，经历几个不同的生长阶段。2. 氧化气体、空气传播颗粒和环境烟草烟雾是常见的空气污染物，在生命的产前和产后阶段都可能对肺部产生重大影响。尽管接触这些污染物的特定靶细胞尚未明确确定，但这些细胞可能会影响肺发育不同阶段表达的关键信号或介质。3. 新生儿对环境污染物的易感性可能是由于对几种细胞类型的直接或间接打击，从而影响细胞分化、增殖和/或成熟。空气污染物还可能改变在子宫内和出生后生长过程中不断变化的代谢、免疫和神经功能的正常发育模式。4. 新生儿细胞对环境损伤的敏感性可能与成体中发现的相同细胞类型完全不同。与出生后时期相比，胎儿期向呼吸系统输送环境毒物的情况也有很大差异。在评估早期生命中环境毒物的影响时，必须考虑环境因素通过其他器官系统和脉管系统的传递和相互作用，以及母体的影响。5. 要了解儿童呼吸系统接触各种环境因素的健康后果，需要仔细考虑肺发育是一个多步骤过程，不能基于对成人的研究。
