The effects of vitamin A supplementation on the production of hypersensitive inflammatory mediators of ammonia-induced airways of pigs

Abstract

Ammonia utilised for various purposes in the field of agriculture is considered one of the most hazardous pollutants, and is known to irritate the airways of farmers and animals. Vitamin A may participate in the modulation of host immune and inflammatory responses. In this study, the beneficial effects of vitamin A supplementation on ammonia-induced pulmonary inflammation and also lung stress due to suboptimal environmental temperature were examined. The results showed that ammonia inhalation significantly increased thromboxane A 2 (TXA 2 ) and leukotriene C 4 (LTC 4 ) production by the lungs, while vitamin A supplementation significantly reduced the production of TXA 2 and LTC 4 and it also enhanced prostaglandin I 2 (PGI 2 ) in ammonia-induced inflammatory lungs and increased PGI 2 production in the lungs of pigs raised at suboptimal environmental temperature. Thus, exposure to ammonia produces a disruptive defect in the lungs and vitamin A supplementation may relieve this detriment by modulating the production of pulmonary inflammatory mediators.