Effect of vitamin A deficiency on mammary gland development and susceptibility to mastitis through intramammary infusion with Staphylococcus aureus in mice.
Weanling mice were fed 0 or 150 micrograms retinol equivalent/kg of diet for 5 weeks, were bred, and allowed to complete gestation. On day 3 of lactation, all mice were separated from their litters for 1 hour and were then anesthetized. The 4th right or left mammary gland was inoculated with 0.1 ml of S Aureus (10(10) colony-forming units/0.1 ml). Exactly 24 hours after inoculation, the mice were euthanatized and the mammary glands were removed and fixed for histologic evaluations. Vitamin A-deficient dams had smaller litter size and lower liver stores of vitamin A; however, deficiency was not severe enough to produce external signs of vitamin A deficiency in the dams. Morphologic studies showed large areas of adipose tissue, greatly reduced ductal and lobule-alveolar development, and decreased total secretory activity in mammary glands from vitamin A-deficient females. On the other hand, mammary glands from vitamin A-supplemented mice had extensive lobule-alveolar development and highly distended alveoli. Extensive necrosis of alveolar tissue was observed in staphylococcus-infused mammary glands of all mice. Large numbers of leukocytes and cell debris were present in the lumen of alveoli and ducts. However, mammary glands from vitamin A-deficient females had more extensive pathologic damage compared with corresponding glands from vitamin A-supplemented mice. Results indicted that vitamin A-deficient mice had reduced mammary development and increased pathologic damage to the mammary gland after intramammary challenge with staphylococcus.
D000818:Animals; D004195:Disease Models, Animal; D004198:Disease Susceptibility; D005260:Female; D008321:Mammary Glands, Animal / Q000254:growth & development* / Q000473:pathology; D008413:Mastitis / Q000473:pathology / Q000662:veterinary*; D051379:Mice; D008815:Mice, Inbred Strains; D011247:Pregnancy; D012376:Rodent Diseases / Q000473:pathology; D013203:Staphylococcal Infections / Q000473:pathology / Q000662:veterinary*; D014802:Vitamin A Deficiency / Q000473:pathology / Q000662:veterinary*