Rc. Baybutt et al., Vitamin A deficiency injures lung and liver parenchyma and impairs function of rat type II pneumocytes, J NUTR, 130(5), 2000, pp. 1159-1165
The purpose of this research was to determine the effects of vitamin A defi
ciency on liver and lung morphology and type II pneumocyte function. Weanli
ng rats were fed a retinol-adequate (control) or -deficient diet for 6 wk,
Average food intakes and body weights were not different between the vitami
n A-deficient and -adequate rats. Histologic examination revealed that the
lungs of vitamin A-deficient rats had less collagen in the adventitia of sm
all caliber arteries and arterioles and in the alveolar septa, which appear
ed thinner than that of controls. Many areas of the lungs of the same rats
were also emphysematous (increased size of air spaces distal to the termina
l bronchiole, with thinning and partial or total destruction of septal wall
). Content of elastin also was lower in the lung parenchyma, as well as in
the small arteries and arterioles, but not in the larger ones. Peribronchia
l collagen was not affected by the deficient diet, Scattered inflammation w
as observed in most of the vitamin A-deficient rats; a mild inflammatory re
action also was seen in one of the controls. Vitamin A-deficient rats also
exhibited hepatocyte vacuolization and mild inflammation in the liver, spec
ifically in the periportal tracts. Surfactant synthesis and ornithine decar
boxylase activity were significantly lower in type II pneumocytes isolated
from vitamin A-deficient rats. In conclusion, our data provide evidence tha
t vitamin A deficiency produces profound morphologic alterations in liver a
nd lung parenchyma and impairs pneumocyte function.