Postnatal development of rat lung. Changes in lung lectin, elastin, acetylcholinesterase and other enzymes.
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.
D000110:Acetylcholinesterase / Q000378:metabolism*; D000373:Agglutinins / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D004549:Elastin / Q000378:metabolism*; D005697:Galactosides / Q000378:metabolism*; D037161:Galectins; D006027:Glycosides / Q000378:metabolism*; D006388:Hemagglutinins / Q000378:metabolism*; D037102:Lectins / Q000378:metabolism*; D008168:Lung / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D051381:Rats
D000373:Agglutinins; D002352:Carrier Proteins; D005697:Galactosides; D037161:Galectins; D006027:Glycosides; D006388:Hemagglutinins; D037102:Lectins; D004549:Elastin; D000110:Acetylcholinesterase