Postnatal undernutrition slows development of bronchiolar epithelium in rats.
The lung's small conducting airways are sites of dysfunction early in the course of chronic lung diseases that are prevalent in humans; furthermore, there is evidence that aspects of childhood environment may adversely influence small airway function in adulthood. Because there is considerable early postnatal morphological maturation of the bronchiolar epithelium in rats, these considerations led to the present study in which we assessed the effect of early postnatal undernutrition in rats on the anatomic development of the bronchiolar epithelium. We found undernutrition, produced by increasing rat litter size shortly after birth, led to delayed development of the mitochondria and rough endoplasmic reticulum of bronchiolar Clara cells. Of particular interest, underfeeding resulted in considerably diminished mitosis by Clara cells, decreased nuclear numerical density of bronchiolar ciliated cells, evidence of diminished conversion of Clara cells to ciliated cells, and an abnormal cellular composition of the small airway epithelium that persisted well beyond the period of underfeeding. We conclude that early neonatal events can have long-term effects on the bronchiolar epithelium.
Massaro
G D
GD
Pulmonary Research Laboratories, Calvin and Flavia Oak Asthma Research and Treatment Facility, University of Miami School of Medicine 33136.
McCoy
L
L
Massaro
D
D
D000375:Aging; D000818:Animals; D001980:Bronchi / Q000254:growth & development* / Q000473:pathology / Q000648:ultrastructure; D002923:Cilia / Q000648:ultrastructure; D004847:Epithelial Cells; D004848:Epithelium / Q000648:ultrastructure; D005260:Female; D008297:Male; D009748:Nutrition Disorders / Q000503:physiopathology*; D015388:Organelles / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values