title: Periconceptional undernutrition and being a twin each alter kidney development in the sheep fetus during early gestation.
abstract: Adaptive growth responses of the embryo and fetus to nutritional restraint are important in ensuring early survival, but they are implicated in the programming of hypertension. It has been demonstrated that kidney growth and nephrogenesis are each regulated by intrarenal factors, including the insulin-like growth factors, glucocorticoids, and the renin-angiotensin system. Therefore, we have investigated the impact of periconceptional undernutrition (PCUN; from approximately 6 wk before to 7 days after conception) in singleton (control, n = 18; PCUN, n = 16) and twin pregnancies (control, n = 6; PCUN, n = 5) on the renal mRNA expression of 11beta- hydroxysteroid dehydrogensase type 1 and type 2 (11beta-HSD-1 and -2), the glucocorticoid (GR), and mineralocorticoid receptors, angiotensinogen, angiotensin receptor type 1 (AT1R) and 2 (AT2R), IGF-1 and IGF-2, and IGF1R and IGF2R at approximately 55 days gestation. There was no effect of PCUN or fetal number on fetal weight on relative kidney weight at approximately day 55 of gestation. There was an inverse relationship between the relative weight of the fetal kidney at approximately day 55 and maternal weight loss during the periconceptional period in fetuses exposed to PCUN. Exposure to PCUN resulted in a higher expression of IGF1 in the fetal kidney in singleton and twin pregnancies. Being a twin resulted in higher intrarenal expression of IGF-1 and IGF-2, GR, angiotensinogen, AT1R, and AT2R mRNA at 55 days gestation. Renal 11beta-HSD-2 mRNA expression was higher in PCUN singletons, but not PCUN twins, compared with controls. Thus, there may be an adaptive response in the kidney to the early environment of a twin pregnancy, which precedes the fetal growth restriction that occurs later in pregnancy. The kidney of the twin fetus exposed to periconceptional undernutrition may also be less protected from the consequences of glucocorticoid exposure.
authors.affiliation: Early Origins of Adult Health Research Group, Sansom Institute of Health Research, School of Pharmacy and Medical Sciences, Univ. of South Australia, Adelaide, SA 5000, Australia.
authors.forename: Severence M
authors.initials: SM
authors.lastname: MacLaughlin
authors.forename: Simon K
authors.initials: SK
authors.lastname: Walker
authors.forename: David O
authors.initials: DO
authors.lastname: Kleemann
authors.forename: Darran N
authors.initials: DN
authors.lastname: Tosh
authors.forename: I Caroline
authors.initials: IC
authors.lastname: McMillen
mesh_terms: D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1 / Q000235:genetics; D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2 / Q000235:genetics; D000808:Angiotensinogen / Q000235:genetics; D000818:Animals; D001835:Body Weight; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D005865:Gestational Age; D006977:Hypertension, Renal / Q000473:pathology / Q000503:physiopathology*; D007334:Insulin-Like Growth Factor I / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000235:genetics; D007668:Kidney / Q000196:embryology* / Q000473:pathology / Q000502:physiology*; D044342:Malnutrition / Q000503:physiopathology*; D009929:Organ Size; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000503:physiopathology*; D012333:RNA, Messenger / Q000378:metabolism; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics; D044139:Receptor, Angiotensin, Type 2 / Q000235:genetics; D011965:Receptors, Glucocorticoid / Q000235:genetics; D012756:Sheep; D014427:Twins
chemical_list: D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011965:Receptors, Glucocorticoid; D000808:Angiotensinogen; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1; D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2