AJP - Regulatory, Integrative and Comparative Physiology, Vol 251, Issue 3 470-R475, Copyright © 1986 by American Physiological Society
Perinatal anatomic development of alveolar type II cells in rats
G. D. Massaro, L. Clerch and D. Massaro
We studied the perinatal development of rat alveolar type II cells. The
volume density (Vv) of lamellar bodies increased twofold from gestational
day 21.5 to postnatal day 1 and 1.6-fold between age 1 and 60 days. The Vv
of glycogen areas fell sharply between late gestation and postnatal day 1;
this decrease was greater in pups delivered from dexamethasone- compared
with diluent-treated dams. In utero administration of glucagon to fetuses
on gestational day 21.5 caused a decline in the Vv of glycogen areas within
4 h. Pups from dams underfed in late gestation had a higher Vv of glycogen
areas and a lower Vv of lamellar bodies on the first 2 postnatal days
compared with pups from dams allowed food ad libitum. We conclude that rat
alveolar type II cells are somewhat immature at birth; prenatal maternal
underfeeding slows the pre- and postnatal maturation of alveolar type II
cells; and 3) exogenous glucagon causes a fall in the Vv of glycogen areas
in type II cells of fetal rats at gestational day 21.5.
