AJP - Lung Cellular and Molecular Physiology, Vol 257, Issue 2 80-L85, Copyright © 1989 by American Physiological Society
Brief perinatal hypoxia impairs postnatal development of the bronchiolar epithelium
G. D. Massaro, J. Olivier and D. Massaro
Calvin and Flavia Oak Asthma Research and Treatment Facility, University of Miami School of Medicine, Florida 33136.
We placed pregnant rats in 10% O2 on the last day of gestation for less
than or equal to 9 h plus 1-2 h (with their pups) after the onset of
delivery. In the pups this brief perinatal hypoxia led to an altered
cellular composition of the bronchiolar epithelium that persisted at least
to age 30 days; it was characterized by a higher nuclear numerical density
(Nvn) of Clara cells, a lower Nvn of ciliated cells, and a lower percentage
and Nvn of Clara cells in mitoses compared with control rats. The perinatal
hypoxia also led to a significantly lower volume and volume density of the
secretory apparatus (rough endoplasmic reticulum and secretory granules) on
day 7 in 10% O2-born rats. The data on the Nvn of Clara and ciliated cells
and on Clara cell mitoses are consistent with the notion that exposure to
10% O2 impaired the differentiation of Clara cells into ciliated cells and
this impairment persisted well beyond the period of exposure.
