retinaldehyde and tamibarotene

Retinoic acid (RA) is converted from retinal by retinaldehyde dehydrogenases (RALDHs) and is an essential signaling molecule in embryonic and adult tissue. We previously reported that RALDH1 was produced in the rat anterior pituitary gland and hypothesized that RA was generated in the gland. Midkine (MK) is an RA-inducible growth factor, and MK production in the rat anterior pituitary gland was recently reported. However, the mechanism that regulates gene expression of MK in the pituitary gland has not been determined. To investigate regulation of MK production in the anterior pituitary gland, we analyzed changes in MK mRNA in cultured rat anterior pituitary cells. We identified MK-expressing cells by double-staining with in situ hybridization and immunohistochemical techniques for RALDH1. MK mRNA was expressed in RALDH1-producing cells in the anterior pituitary gland. Using isolated anterior pituitary cells of rats, we examined the effect of RA on gene expression of MK. Quantitative real-time PCR revealed that 72 h exposure to a concentration of 10

Topics: 2-Naphthylamine; Aldehyde Dehydrogenase 1 Family; Animals; Benzoates; Cells, Cultured; Gene Expression Regulation; Intercellular Signaling Peptides and Proteins; Kinetics; Male; Midkine; Nerve Growth Factors; Nerve Tissue Proteins; Neurons; Pituitary Gland, Anterior; Pyrimidines; Rats, Wistar; Receptors, Retinoic Acid; Retinal Dehydrogenase; Retinaldehyde; RNA, Messenger; Signal Transduction; Tetrahydronaphthalenes; Tretinoin; Up-Regulation