Chest
Laboratory and Animal InvestigationsRepeated Allergen Challenge in Rats Increases Vitamin A Consumption
Section snippets
Animals
Highly inbred BN rats (n = 24) were obtained from Harlan. The animals were housed in metal cages in a room with controlled temperature (25 ŷ 2ŶC), relative humidity (65 ŷ 5%), and light (8 am to 6 pm). Ethical permission was obtained for the study, and all procedures were conducted in full compliance with the strict guidelines of the Hebrew University Policy on Animal Care and Use. The rats were weighed at the beginning and end of the study, and their food intake was measured every other day.
Induction of Allergic Bronchitis
Results
There was no difference in food consumption or body weight at the beginning and end of the study between the sensitized (test group) and the naive (control group) rats. The mean NO, TNF-α, percentage of Penh, and concentration of vitamin A in liver, lung, and plasma for the test group and control group rats are shown in Table 1. Bronchoconstriction 5 min after allergen challenge was significantly higher in the sensitized rats compared to the naive rats (p < 0.001).
The plasma and lung vitamin A
Discussion
In this study, we demonstrated that recurrent allergen challenges result in a decrease of hepatic vitamin A stores in sensitized rats. Vitamin A intake was not different between the two groups as was measured by food intake and also expressed by body weight. The liver supplies vitamin A to the serum and the various organs and maintains normal serum and tissue concentration as long as vitamin A is not depleted.14 A decrease of hepatic vitamin A stores might be a result of an increased demand of
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