title: Expression of retinaldehyde dehydrogenase (RALDH)2 and RALDH3 but not RALDH1 in the developing anterior pituitary glands of rats.
abstract: Retinoic acid (RA) plays an important role in cell growth and tissue development and is also a regulating factor of pituitary function. However, whether RA is generated in the pituitary gland and plays a role as a paracrine and/or autocrine hormone is generally unknown. RA is synthesized from retinoids through oxidation processes. Dehydrogenases catalyzing the oxidation of retinal to RA are members of the retinaldehyde dehydrogenase (RALDH) family. In this study, we examined the expression of RALDH1, RALDH2, and RALDH3 mRNA in the rat embryonic pituitary gland. By in situ hybridization with digoxigenin-labeled cRNA probes, we detected mRNA expression for RALDH2 and RALDH3, but not RALDH1. The expression of RALDH2 and RALDH3 was located in Rathke's pouch at embryonic day 12.5 (E12.5) and subsequently in the developing anterior pituitary gland. We also used quantitative real-time polymerase chain reaction to analyze RALDH2 and RALDH3 mRNA expression levels during the development of the pituitary gland. We found that pituitary RALDH2 and RALDH3 mRNA levels were high at E17.5 and decreased markedly after birth. Our study is the first to show that RALDH2 and RALDH3, but not RALDH1, are expressed in the embryonic anterior pituitary gland of the rat.
authors.affiliation: Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University, School of Medicine, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329-0498, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Maekawa
authors.forename: Motoshi
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Shu
authors.initials: S
authors.lastname: Takigami
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Yada
authors.forename: Takashi
authors.initials: T
authors.lastname: Yashiro
mesh_terms: D000080924:Aldehyde Dehydrogenase 1 Family; D000445:Aldehyde Oxidoreductases / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000196:embryology* / Q000201:enzymology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D050697:Retinal Dehydrogenase / Q000235:genetics* / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D000445:Aldehyde Oxidoreductases; D000080924:Aldehyde Dehydrogenase 1 Family; C523119:Aldh1a1 protein, rat; C521403:Aldh1a2 protein, rat; C523120:Aldh1a3 protein, rat; D050697:Retinal Dehydrogenase