Non esterified fatty acids

Total lipid was extracted from mouse livers as previously described (Tan et al., 2011 (link)). Briefly, mouse liver was first homogenized in 2× phosphate buffered saline. Hepatic lipids were extracted from pulverized liver tissue with methanol:chloroform (2:1), dried in an evaporating centrifuge, and resuspended in 5% fat-free bovine serum albumin. Hepatic triglyceride (Thermo Scientific, Middletown, VA) non-esterified fatty acids (Sigma Aldrich, St. Louis MO) were determined using standard kits. Values were normalized to initial liver tissue weight.

Acute exercise responses for blood glucose (Accu-Chek Aviva Plus Glucometer; Roche Diagnostic, Indianapolis, IN), β-hydroxybutyrate (Nova Blood Ketone Monitor; Nova Biomedical, Waltham, MA) and lactate (Lactate Plus Meter; Nova Biomedical, Waltham, MA) were measured via tail vein in conscious mice before and after acute exercise at the end of week 5 (Figure 1A). Serum lipids were analyzed by measuring non-esterified fatty acids (Wako Chemicals, Richmond, VA) and triglycerides (Sigma, St. Louis, MO). ELISA kits were used to detect serum insulin (Mercodia, Uppsala, Sweden; Cat#10–1247-01) and serum corticosterone (Enzo Life Sciences, Farmingdale, NY; Cat# ADI-900–097). Manufacturer’s recommended protocols were used for all measurements.