Contour xt

Lidocaine cream was applied over the rabbit ears 1 h before initiating the infusion procedure, under fasting conditions (gestational 30). The protocol for ¹³C-labeled glucose infusion (GLC group) was based on the method described by Habber et al. in pregnant New Zealand rabbits [24 (link)]. Thus, each rabbit was covered with a surgical cloth and left in a standard rat cage, to relieve stress and avoid sudden movements, respectively. The blood glucose level was measured with a glucometer (Contour XT, Bayer, Basel, Switzerland) before initiating the infusion, by fine puncture in the contralateral ear vein. Then, the marginal ear vein was cannulated with a 24 G catheter (Abbocath, Becton Dickinson, Utah, USA) and 1-¹³C-glucose (28 mM in saline) (99% 1-¹³C-glucose, Sigma-Aldrich, Schnelldorf, Germany) infused at a constant rate (0.2 mL · min^-1 · kg^-1) for 90 min. At 80 min of infusion, anesthesia was induced (ketamina-xylazine i.m., as before) and the animal transferred to the surgical table once asleep (90 min of infusion), where anesthesia, oxygen delivery and heating were performed as before. Infusion of 1-¹³C-glucose was maintained for another 20 min (375 mM in saline, same rate), while the animal was prepared for cesarean section. The mother’s blood glucose level was monitored once more at the end of the infusion (as before).

Animals were fasted during 4 hours prior to termination. Blood was collected and serum glucose levels were measured with glucose meter (Bayer Contour XT). The insulin concentration was analyzed using ELISA Mouse insulin kit (No. 10-1247-01; Mercodia).

Mice were fasted for a 6-hour period and a small incision made in the distal tail vein, from which baseline (and all subsequent) blood glucose measurements were taken. Mice were then given a glucose bolus (2 g/Kg body weight, water solution, intraperitoneal injection) and blood glucose measurements were taken using a Contour XT glucometer (Bayer) at 15, 30, 60 and 120 min.