Epithelial cell distribution and abundance in rhesus monkey airways during postnatal lung growth and development

Laura S. Van Winkle, Michelle V. Fanucchi, Lisa Miller, Gregory L. Baker, Laurel J Gershwin, Edward S Schelegle, Dallas M. Hyde, Michael J. Evans, Charles Plopper

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

Lung development is both a pre- and postnatal process. Although many lung diseases have their origins in early childhood, few quantitative data are available on the normal growth and differentiation of both the conducting airways and the airway epithelium during the postnatal period. We examined rhesus monkey lungs from five postnatal ages: 4-6 days and 1, 2, 3, and 6 mo. Airways increase significantly in both length and circumference as monkeys increase significantly in body weight from 5 days to 6 mo. In this study we asked: as basement membrane surface area increases, does the epithelial cell organization change? To answer this question, we quantified total epithelial cell mass using high-resolution light micrographs and morphometric techniques on sections from defined airway regions: trachea, proximal intrapulmonary bronchus (generations 1 or 2), and distal intrapulmonary bronchus (generations 6-8). Epithelial thickness decreased in the smaller, more distal, airways compared with trachea but did not change with age in the trachea and proximal bronchus. The volume fraction of all cell types measured did not change significantly. Ciliated cells in the distal bronchus and goblet cells in the trachea both decreased in abundance with increasing age. Overall, the epithelial cell populations changed little in terms of mass or relative abundance to each other during this period of active postnatal lung growth. Regarding the proximal conducting airway epithelium, we conclude that 1) the steady-state abundance is tightly regulated to keep the proportion of cell types constant, and 2) establishment of these cell types occurs before 4-6 days postnatal age. We conclude that growth of the proximal airways occurs primarily in length and lags behind that of the lung parenchyma.

Original languageEnglish (US)
Pages (from-to)2355-2363
Number of pages9
JournalJournal of Applied Physiology
Volume97
Issue number6
DOIs
StatePublished - Dec 2004

    Fingerprint

Keywords

  • Airway size
  • Bronchi
  • Epithelial cell mass
  • Morphometry
  • Trachea

ASJC Scopus subject areas

  • Physiology
  • Endocrinology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this