Effect of dietary vitamin A on the mixed function oxidases and the pneumotoxicity of 3-methylindole in goats.
To determine the effects of dietary vitamin A on the activity of the mixed function oxidase (MFO) system and on the susceptibility to 3-methylindole (3MI)-induced respiratory disease, goats were fed a high (supplemented with 12 000 IU retinyl palmitate/kg) or a low (no supplementation) vitamin A diet for 14 weeks. Four animals in each dietary group were then challenged with [14C]3MI. The remaining four animals served as controls. Enzyme assays were performed and severity of the 3MI-induced lung damage was scored. Consumption of the low vitamin A diet resulted in a significant reduction in the liver and lung contents of vitamin A; however, serum concentration of vitamin A was unaffected. High vitamin A supplementation did not alter the activity of the MFO system. Clinical signs, lung - body weight ratio and wet - dry weight ratio of the lungs of 3MI-infused goats were not significantly different; however, in the low vitamin A goats, the microscopic lesions such as the extent of alveolar epithelial hyperplasia were judged to be significantly more severe than those observed in the high vitamin A goats.
D000818:Animals; D001835:Body Weight; D004032:Diet; D006041:Goats / Q000502:physiology*; D007211:Indoles / Q000633:toxicity*; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D009929:Organ Size; D012862:Skatole / Q000633:toxicity*; D014801:Vitamin A / Q000378:metabolism / Q000494:pharmacology*
D007211:Indoles; D014801:Vitamin A; D012862:Skatole; D006899:Mixed Function Oxygenases