Medicine and Health Sciences Commons^™

Evidence Of Increased Hypoxia Signaling In Fetal Liver From Maternal Nutrient Restriction In Mice., Bethany N Radford, Victor K M Han

Paediatrics Publications

BACKGROUND: Intrauterine growth restriction (IUGR) is a pregnancy condition where fetal growth is reduced, and offspring from IUGR pregnancies are at increased risk for type II diabetes as adults. The liver is susceptible to fetal undernutrition experienced by IUGR infants and animal models of growth restriction. This study aimed to examine hepatic expression changes in a maternal nutrient restriction (MNR) mouse model of IUGR to understand fetal adaptations that influence adult metabolism.

METHODS: Liver samples of male offspring from MNR (70% of ad libitum starting at E6.5) or control pregnancies were obtained at E18.5 and differential expression was assessed by …

App21 Transgenic Rats Develop Age-Dependent Cognitive Impairment And Microglia Accumulation Within White Matter Tracts., Nina Weishaupt, Qingfan Liu, Sheojung Shin, Ramandeep Singh, Yuksel Agca, Cansu Agca, Vladimir Hachinski, Shawn Narain Whitehead

Paediatrics Publications

Background

Most of the animal models commonly used for preclinical research into Alzheimer's disease (AD) largely fail to address the pathophysiology, including the impact of known risk factors, of the widely diagnosed sporadic form of the disease. Here, we use a transgenic rat (APP21) that does not develop AD-like pathology spontaneously with age, but does develop pathology following vascular stress. To further the potential of this novel rat model as a much-needed pre-clinical animal model of sporadic AD, we characterize APP21 transgenic rats behaviorally and histologically up to 19 months of age.

Methods

The open field test was used as …

The Expression Of Ovine Placental Lactogen, Star And Progesterone-Associated Steroidogenic Enzymes In Placentae Of Overnourished Growing Adolescent Ewes., Richard G Lea, Peter Wooding, Ian Stewart, Lisa T Hannah, Stephen Morton, Karen Wallace, Raymond P Aitken, John S Milne, Timothy Regnault, Russell V Anthony, Jacqueline M Wallace

Paediatrics Publications

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- …

Altered Placental And Fetal Expression Of Igfs And Igf-Binding Proteins Associated With Intrauterine Growth Restriction In Fetal Sheep During Early And Mid-Pregnancy., Barbra De Vrijer, Meredith L Davidsen, Randall B Wilkening, Russell V Anthony, Timothy Regnault

Paediatrics Publications

The insulin-like growth factors (IGFs) are postulated to be altered in association with the development of intrauterine growth restriction (IUGR). The present studies examined placental and fetal hepatic mRNA concentration of components of the IGF system at two time points (55 and 90 d gestational age, dGA; Term 147 dGA) in a hyperthermia (HT)-induced sheep model of placental insufficiency-IUGR. Maternal plasma insulin and IGF-I were constant at 55 and 90 dGA and were unaffected by treatment. Umbilical vein insulin concentrations tended to be reduced at 90 dGA following HT exposure. Caruncle IGF-I mRNA was increased at 90 dGA in HT …

Investigating The Causes Of Low Birth Weight In Contrasting Ovine Paradigms., J M Wallace, Timothy Regnault, S W Limesand, W W Hay, R V Anthony

Paediatrics Publications

Intrauterine growth restriction (IUGR) still accounts for a large incidence of infant mortality and morbidity worldwide. Many of the circulatory and transport properties of the sheep placenta are similar to those of the human placenta and as such, the pregnant sheep offers an excellent model in which to study the development of IUGR. Two natural models of ovine IUGR are those of hyperthermic exposure during pregnancy, and adolescent overfeeding, also during pregnancy. Both models yield significantly reduced placental weights and an asymmetrically growth-restricted fetus, and display altered maternal hormone concentrations, indicative of an impaired trophoblast capacity. Additionally, impaired placental angiogenesis …