Distribution of All-trans-Retinoic Acid in Normal and Vitamin A Deficient Mice: Correlation to Retinoic Acid Receptors in Different Tissues of Normal Mice

Abstract

The distribution of all-trans-retinoic acid (RA) was investigated using whole body autoradiography of normal and partial vitamin A deficient (VAD) mice. Retinoic acid receptors (α, β, and γ) were also studied in normal mice using immunoblotting. Normal and VAD mice were injected with 5 μCi 11CRA. The distribution of RA was quantitatively studied using a computer-assisted image analysis system. 11CRA was incorporated 0.5 hr after RA administration in both normal and VAD mice, while the labelling peak was at 6 hr in most organs in normal and VAD mice. The most intense labeling was found in liver, kidney, intestine, lung, Harderian gland, and salivary gland at all time points. A band of M, 51K was found in all mouse tissues by immunoblotting using the polyclonal antibody RAR82 against total RARs or the RARα specific monoclonal antibody Rα13. In some tissue, an additional band of 55-58K was also found. Lung, large intestine, small intestine, testis, seminal vesicle, and spleen contained highest concentration of total RARs, while heart, lung, small intestine, spleen, salivary gland, and preputial gland had the highest concentration of RARα. The uptake of labeled RA correlated well with RAR or RARα concentration in the corresponding tissues.