Wittmann J
Tierarztl Prax Suppl. 1987;2:33-6.
With the development of higher organisms, the problem of gas exchange of each single cell had to be resolved. Nature gave preference to the development of a specific organ for gas exchange (lungs, gills) as opposed to a system of gas exchange involving the whole organism. In vertebrates, the latter has been developed only in lungless salamanders (Desmognatus fuscus) and in the embryos of the oviparous species. Mammalian embryos also do not use their lungs during the prenatal period, however, in contrast to the oviparous species gas exchange is performed via the maternal respiratory apparatus. The transition from the pre- to the neonatal period is more problematic in mammals than in oviparous species. The critical situation is caused by the fact that mammalian lungs must be inflated within a comparatively short period of time. In oviparous species, however, the development of lung respiration lasts several hours. Several lines of evidence indicate that lungs are also involved in blood pressure changes occurring during the perinatal period. In this context the pulmonary regulation of bradykinin and prostaglandin metabolism has been emphasized. It has been recognized that lungs of adults serve not only as a gas exchange organ, but are involved in the synthesis, activation or inactivation of substances which exert an influence mainly on blood pressure. In this function, lungs are especially suitable due to their position between the venous and arterial circulation. Therefore, it is not surprising that disturbances in the pulmonary function result in manifold pathological processes.
随着高等生物的进化，单个细胞的气体交换问题必须得到解决。自然界更倾向于发育一个特定的气体交换器官（肺、鳃），而不是涉及整个生物体的气体交换系统。在脊椎动物中，后者仅在无肺蝾螈（Desmognatus fuscus）和卵生物种的胚胎中得到发展。哺乳动物胚胎在产前阶段也不使用肺部，然而，与卵生物种不同的是，气体交换是通过母体呼吸系统进行的。从产前到新生儿期的过渡在哺乳动物中比在卵生物种中更成问题。关键情况是由于哺乳动物的肺部必须在相对较短的时间内充气。然而，在卵生物种中，肺呼吸的发育持续数小时。有几条证据表明，肺也参与围产期发生的血压变化。在这种情况下，缓激肽和前列腺素代谢的肺调节受到了强调。人们已经认识到，成年动物的肺不仅作为气体交换器官，而且参与主要对血压产生影响的物质的合成、激活或失活。在这个功能中，肺因其在静脉和动脉循环之间的位置而特别合适。因此，肺功能紊乱导致多种病理过程也就不足为奇了。
