Maternal protein restriction regulates IGF2 system in placental labyrinth.
This study was to test the hypothesis that altered IGF2 system in the placental labyrinth zone (LZ) impairs feto-placental growth in response to maternal protein restriction. Rats were fed a 20% protein diet and an isocaloric 6 % protein diet (LP) from day 1 to days 14, 18, or 21 of pregnancy. The effects of diet, gender of placenta and fetus, and day of pregnancy on placental weight, fetal weight, and expression of the IGF2 axis in the placental LZ and amino acids in maternal plasma were analyzed. Growth restriction occurred in both female and male fetuses by LP, coincident with impaired LZ growth and efficiency. The expression of Igf2, Igf2P0, Igf1r, Igf2r, Insr, Igfbp1, and Igfbp2 in placental LZ were affected by diet, gender and/or day of pregnancy. Concentrations of total essential amino acids and total nonessential amino acids were reduced and increased, respectively, in maternal plasma of LP-fed rats. These results indicate that adaptation of the IGF2 system in rat LZ occurs in a sex- and time-dependent manner in response to maternal protein restriction; however, these adaptations cannot prevent the growth restriction of both male and female fetuses during late pregnancy.
Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX 77555-1062, USA.
Haijun
H
Gao
Kunju Reddiar
KR
Sathishkumar
Uma
U
Yallampalli
Meena
M
Balakrishnan
Xilong
X
Li
Guoyao
G
Wu
Chandra
C
Yallampalli
D000818:Animals; D004044:Dietary Proteins / Q000008:administration & dosage*; D005260:Female; D007335:Insulin-Like Growth Factor II / Q000235:genetics / Q000502:physiology*; D009929:Organ Size; D010920:Placenta / Q000502:physiology*; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction
D004044:Dietary Proteins; D012333:RNA, Messenger; D007335:Insulin-Like Growth Factor II