The fine structure of vitamin A deficiency. I. Parotid duct metaplasia
Hayes, K.C.; Mccombs, H.L.; Faherty, T.P.
Laboratory Investigation; a Journal of Technical Methods and Pathology 22(1): 81-89
1970
ISSN/ISBN: 0023-6837 PMID: 5410512 Document Number: 20632
Six calves were reared for 35 days on whole milk, limited calf starter and unrestricted lucerne hay and were then transferred to a vitamin A depletion diet with insufficient or enough vitamin A, either 8 or 108 mu g retinyl acetate per kg bodyweight daily. After 25 weeks mean plasma vitamin A values in the 2 groups were 12 and 34 mu g per 100ml and cerebrospinal fluid pressures were 344 and 91 mm saline. Sections of parotid duct epithelium were examined. The epithelium in control calves appeared to have 2 cell types, mucoid and fibrous. The mucoid cell had cisternal profiles of granular reticulum, extensive Golgi membranes and dense aggregates of intracytoplasmic mucin. Fibrous cells showed cytoplasmic tonofibrils and a scarcity of granular endoplasmic reticulum and Golgi membranes. In the deficient calves mucoid cells were rare and fibrous cells predominated without evidence of keratinisation. It is suggested that vitamin A deficiency prevented the activation or differentiation of mucus-producing cells.