title: Decreased expression of a novel prostaglandin transporter, OAT-PG, facilitates renocortical PGE2 accumulation during rat pregnancy.
abstract: BACKGROUND
  Prostaglandin (PG)-specific organic anion transporter (OAT-PG) is a recently identified renal transporter involved in the local clearance of prostaglandin E2 (PGE2). Since the renal biosynthesis of PGE2 is not increased during pregnancy, this transporter expression would affect the gestational changes in the renal PGE2 content.
  
  
  METHODS
  Kidneys from rats at different gestational stages were used to examine gestational changes in the renocortical PGE2 concentration. The renal expression of OAT-PG and the enzymes for PGE2 synthesis was also examined sequentially, together with the gestational changes in renal renin production.
  
  
  RESULTS
  The renocortical PGE2 concentration was significantly increased during midterm to late pregnancy, with a maximum increase of 47.6 ± 11.5% from the virgin value. Although the expression of the enzymes, such as cyclooxygenases and PG synthases, was not increased, that of OAT-PG was significantly decreased throughout pregnancy, inversely correlating with changes in the renocortical PGE2 concentration. Renal renin production was significantly increased during pregnancy.
  
  
  CONCLUSIONS
  This study demonstrated for the first time that the tissue PGE2 concentration was increased in pregnant rat kidneys, which may be associated with the gestational rise in glomerular filtration rate. The decreased expression of OAT-PG was thought to be responsible for the increased tissue PGE2 content.
authors.affiliation: Department of Physiology I, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Itsuro
authors.initials: I
authors.lastname: Kazama
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Matsubara
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Kanai
authors.forename: Ryo
authors.initials: R
authors.lastname: Hatano
authors.forename: Shinji
authors.initials: S
authors.lastname: Asano
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Endo
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Toyama
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ejima
authors.forename: Shin
authors.initials: S
authors.lastname: Kurosawa
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Maruyama
mesh_terms: D000818:Animals; D051545:Cyclooxygenase 1 / Q000235:genetics / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006911:Hydroxyprostaglandin Dehydrogenases / Q000235:genetics / Q000378:metabolism; D019746:Intramolecular Oxidoreductases / Q000235:genetics / Q000378:metabolism; D007668:Kidney / Q000201:enzymology / Q000378:metabolism*; D008137:Longitudinal Studies; D027361:Organic Anion Transporters / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D011247:Pregnancy; D000071876:Prostaglandin-E Synthases; D012313:RNA / Q000737:chemistry / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D012083:Renin / Q000235:genetics / Q000378:metabolism
chemical_list: D027361:Organic Anion Transporters; C570643:Slc22a22 protein, rat; D012313:RNA; D006911:Hydroxyprostaglandin Dehydrogenases; C035859:15-hydroxyprostaglandin dehydrogenase; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D012083:Renin; D019746:Intramolecular Oxidoreductases; D000071876:Prostaglandin-E Synthases; D015232:Dinoprostone