Rat chow

Male and nulliparous female Wistar rats (n ​= ​4, n ​= ​38, respectively) were obtained from the Animal Resource Centre (ARC, Western Australia) at 8–10 weeks of age. Housing (41.5 ​× ​28 ​× ​22 ​cm wire-top cages; Mascot Wire Works, Australia) and food (Rat Chow, Specialty Feeds, Western Australia) were consistently maintained with a 12-h light/dark schedule (lights on at 7:00 a.m.) and a constant temperature of 20 ​°C ​± ​2. The animals were acclimated for 1 week before daily monitoring of the female oestrous cycle began, using an impedance probe. On the day of proestrus females were mated with male rats overnight. The following morning, the presence of sperm via vaginal smear was used to identify the day of conception, identified as gestational day (GD) 0. Pregnant dams were then randomly allocated to a treatment group (MIA, n ​= ​20 or saline (SAL), n ​= ​18). All handling of animals and procedures were approved by the University of Newcastle Animal Care and Ethics Committee (A-2016-610).

A rat insulin enzyme-linked immunosorbent assay kit was purchased from Millipore (Billerica, MA, USA), while kits for superoxide dismutase (SOD) and estrogen were from Cell Biolabs (Cell Biolabs Inc, San Diego, CA, USA) and Cusabio Biotech Co Ltd (Wuhan, People’s Republic of China), respectively. The GenomeLab™ GeXP start kit was from Beckman Coulter Inc (Miami, FL, USA) and the RNA extraction kit was from RBC Bioscience Corp (Taipei, Taiwan). MgCl₂ and DNA Taq polymerase were purchased from Thermo Fisher Scientific (Pittsburgh, PA, USA), while RCL2 solution was purchased from Alphelys (Toulouse, France). Glucometer strips were from Roche Diagnostics (Indianapolis, IN, USA) and lipid profile kits (low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total cholesterol, and triglycerides) were purchased from Randox Laboratories Ltd (Crumlin, County Antrim, UK). Rat chow was obtained from Specialty Feeds (Glen Forrest, WA, Australia). Ketamine/xylazine was from Sigma Chemical Co (St Louis, MO, USA) and other solvents of analytical grade were purchased from Merck (Darmstadt, Germany).