2.4.2 Fasting glucose and insulin tolerance test (ITT)
To assess fasting blood glucose, blood was collected through a small
incision at the tip of the tail of the animals, after fasting period of
6 hours (Ayala et al., 2010), and
blood glucose concentration was measured using a glucometer for
determination of fasting blood glucose (mother females and their
offspring).
The ITTs were only performed for the mothers pre- and post-pregnancy
(weeks 8 and 12), since this test cannot be performed during pregnancy
due to insulin administration. In the offspring (males and females),
this test was performed when they completed 60 days of life. After that,
all animals received a dose of 2U/kg of intraperitoneal insulin and
subsequent blood glucose measurements at times 5, 10, 15, 20, 25 and
30min post-insulin injection were performed
(adapted from Wang and Liao,
2012). The animals that presented glucose values below 30mg/dL during
the test were kept warm and received intraperitonially glucose. For
demonstration and data analysis, they were presented as absolute glucose
data (mg/dL), as area under the ITT curve calculated by dividing glucose
data (mg/dL) by the time post-insulin injection (0 to 30min).