Redistribution of vitamin A in tissues of rats with imposed chronic confinement stress.

1. The effect of confinement stress on the metabolism of vitamin A was studied in rats by following changes in tissue distribution of the vitamin for 29 d. In order to minimize predicted errors which might result from fluctuation of vitamin A intake, the effect of the stress was investigated in rats fed on a vitamin A-free diet. 2. Daily stress for 6 h induced an enlargement of the adrenals with a concomitant involution of the thymus and spleen, values returning to normal within 11-15 d. 3. The stress caused an immediate decrease in the content of vitamin A in serum. 4. Feeding rats a vitamin A-free diet resulted in significant increase in the vitamin A content of the kidney. Imposing stress on these rats inhibited markedly the increase in kidney vitamin A content. 5. The stress produced no appreciable change in levels of the vitamin in the liver and testes. 6. There was a preferential accumulation of the vitamin in the adrenals of the stress-imposed rats even though they were fed on a vitamin A-free diet. 7. In conclusion, the results of the present study demonstrated that chronic immobilization stress produced marked tissue-dependent changes in their vitamin A content.