Postnatal development of rat lung. Changes in lung lectin, elastin, acetylcholinesterase and other enzymes.
Postnatal development of rat lung. Changes in lung lectin, elastin, acetylcholinesterase and other enzymes.
复制标题
大鼠肺的出生后发育。
作者：
J. Powell;P. Whitney
大鼠肺从原始气体交换器官到成熟呼吸器官的发育在很大程度上是一种出生后现象，已通过形态学和形态测量方法得到了很好的表征。肺泡化是在生命的前三周内实现的。大鼠肺的胆碱能神经支配也在出生后出现。我们监测了出生后大鼠肺部发育过程中几种蛋白质的存在或活性。新生大鼠肺中含有可忽略不计的乙酰胆碱酯酶，但乙酰胆碱酯酶的比活性在出生后 10-11 天达到成人值。新生大鼠肺不含有大量的 β-半乳糖苷结合蛋白 [Powell (1980) Biochem. J.187, 123-129]。这种内源性肺凝集素的活性在大约第 6 天时很明显，在第 10 天和第 13 天之间达到最大，然后下降 8-10 倍以达到成人值。形态学证据表明弹性蛋白对肺重建至关重要。我们量化了每克湿重中锁链素和异锁链素的含量。肺的。按照这个标准，弹性蛋白的浓度很低并且保持稳定，直到出生后第 7 天；第10天到第20天之间，弹性蛋白浓度急剧增加，达到成人值。肺凝集素活性的峰值与乙酰胆碱酯酶的成熟和弹性蛋白快速交联的开始同时发生。还监测了血管紧张素转换酶、碳酸酐酶、胆碱激酶和葡萄糖6-磷酸脱氢酶的比活性。
The development of rat lung from a primitive gas-exchange organ to the mature respiratory organ is in large part a postnatal phenomenon that has been well characterized by morphological and morphometric methods. The alveolarization of the lung is achieved during the first 3 weeks of life. Cholinergic innervation of rat lung also appears postnatally. We have monitored the presence or activity of several proteins during postnatal rat lung development. Newborn-rat lung contains negligible amounts of acetylcholinesterase, but the specific activity of acetylcholinesterase reaches adult values by postnatal day 10-11. Neonatal-rat lung does not contain significant amounts of beta-galactoside-binding protein [Powell (1980) Biochem. J.187, 123-129]. The activity of this endogenous lung lectin was apparent at about day 6, was maximal between days 10 and 13 before declining 8-10-fold to reach adult values. Elastin has been implicated from morphological evidence as critical to lung restructuring. We have quantified the amount of desmosine and isodesmosine per g wet wt. of lung. The concentration of elastin, by this criterion, was low and stationary until postnatal day 7; a dramatic increase in elastin concentration occurred between days 10 and 20, when adult values were reached. The peak of lung-lectin activity was coincident with the maturation of acetylcholinesterase and the beginning of rapid elastin cross-linking. The specific activities of angiotensin-converting enzyme, carbonic anhydrase, choline kinase and glucose 6-phosphate dehydrogenase were also monitored.