Accu check blood glucose meter

The fasting glucose concentrations in blood samples (0.6 μL) collected weekly from the tail vein using tail vein puncture after 12 h of fasting were measured using an Accu-Check Blood Glucose Meter (Roche, Basel, Switzerland).

Fat and lean mass were measured by body composition analyzer (Meg‐Med MRI system). Whole‐body energy expenditure (VO2, VCO2), food consumption and locomotor activity (beam break counts) were tracked using the comprehensive laboratory animal monitoring system (CLAMS).
For cold tolerance test, mice were housed at 4 °C and core temperature was measured at indicated time with a rectal thermometer (Braintree, TH‐5). For GTT experiments, mice were fasted overnight and then injected intraperitoneally (i.p.) with glucose solution in saline (1.5 g kg⁻¹ body weight). For ITT experiments, the mice were injected i.p. with insulin (1.25 U kg⁻¹ body weight, Sigma). Blood samples from tail vein were collected at indicated time points and glucose levels were measured with an AccuCheck blood glucose meter (Roche Diagnostics Inc.).

Blood glucose level was measured bi-monthly. Blood was collected by retro-orbital sinus puncture with a capillary hematocrit and was estimated using an Accu-Check Blood Glucose Meter (Roche, Manheim, Germany). The serum is obtained by centrifugation of the blood at 5000 rpm for 15 min, 4 °C, aliquot, and stored at −30 °C until used for analysis. Serum concentrations of total cholesterol (TC), total triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT)were assessed by the enzymatic colorimetric method by an Architect C8000 analyzer (Abbott Laboratories, Abbott Park, IL, USA) using the respective reagent kits [42 (link)].
Furthermore, the atherogenic index (AtI) was calculated for different animal groups. It is defined as the ratio of LDL (TC-HDL) and HDL according to the Friedewald equation.
$$\mathrm{AtI}=\frac{\left(\mathrm{TC}-\mathrm{HDL}\right)}{\mathrm{HDL}}$$ P. obesus animals were considered dyslipidemic when TC ≥ 2.00 g/L and/or LDL ≥ 1.60 g/L and/or TG ≥ 1.50 g/L and/or HDL < 0.40 g/L.

First, a sample of blood (1 drop of approximately 10 µL) was collected from the animals fasted for 8 h after making a small cut (of approximately 3 mm) at the extremity of the animal tail, at time zero of the experimental procedure. After the first collection (time zero), regular insulin (0.5 U/kg, Biobrás, São Paulo, Brazil) was injected, and blood samples were collected after 5, 10, 15, 30, 60 and 90 min for glucose measurements using the Accu-check blood glucose meter (Roche Diagnostics, Mannheim, Germany).

The mice fasted for 6 h, and the blood glucose levels of samples obtained from the tail veins were measured using an ACCU-CHECK blood glucose meter (Roche Diagnostics, Mannheim, Germany). The method for collection of blood was to cut off about 1 mm from the tip of the tail after it was disinfected with an alcohol cotton ball. The first drop of venous blood was discarded, and the second drop of blood (0.1 ml) was collected. The tail of the mouse was then pressed for 1 min with a dry cotton ball to stop the bleeding.