The expression of ovine placental lactogen, StAR and progesterone-associated steroidogenic enzymes in placentae of overnourished growing adolescent ewes.

Authors

Richard G Lea
Peter Wooding
Ian Stewart
Lisa T Hannah
Stephen Morton
Karen Wallace
Raymond P Aitken
John S Milne
Timothy Regnault, Western UniversityFollow
Russell V Anthony
Jacqueline M Wallace

Document Type

Article

Publication Date

4-1-2007

Journal

Reproduction

Volume

133

Issue

4

First Page

785

Last Page

796

URL with Digital Object Identifier

https://doi.org/10.1530/REP-06-0294

Abstract

Overnourishing pregnant adolescent sheep promotes maternal growth but reduces placental mass, lamb birth weight and circulating progesterone. This study aimed to determine whether altered progesterone reflected transcript abundance for StAR (cholesterol transporter) and the steroidogenic enzymes (Cyp11A1, Hsd3b and Cyp17). Circulating and placental expression of ovine placental lactogen (oPL) was also investigated. Adolescent ewes with singleton pregnancies were fed high (H) or moderate (M) nutrient intake diets to restrict or support placental growth. Experiment 1: peripheral progesterone and oPL concentrations were measured in H (n=7) and M (n=6) animals across gestation (days 7-140). Experiment 2: progesterone was measured to mid- (day 81; M: n=11, H: n=13) or late gestation (day 130; M: n=21, H: n=22), placental oPL, StAR and steroidogenic enzymes were measured by qPCR and oPL protein by immunohistochemistry. Experiment 1: in H vs M animals, term placental (P