TABLE 1

Basal 5-h fasted data

BL6129FVBDBA
Body weight (g)22.1 ± 0.3*21.2 ± 0.324.2 ± 0.322.5 ± 0.5
Muscle mass (% body wt)77 ± 1*§72 ± 173 ± 170 ± 1
Fat mass (% body wt)9 ± 1*§13 ± 114 ± 118 ± 1
Whole-blood glucose (mmol/l)9.1 ± 0.2§7.1 ± 0.29.1 ± 0.37.8 ± 0.2
Plasma glucose (mmol/l)9.7 ± 0.4§8.6 ± 0.39.2 ± 0.18.8 ± 0.1
Blood glucose:plasma glucose0.96 ± 0.040.84 ± 0.010.95 ± 0.020.90 ± 0.02
Insulin (pmol/l)138 ± 24§90 ± 12114 ± 18198 ± 12
C-peptide (nmol/l)0.59 ± 0.06*0.59 ± 0.060.36 ± 0.060.46 ± 0.06
Glucagon (ng/l)61 ± 7*48 ± 339 ± 360 ± 6
Corticosterone (ng/l)0.17 ± 0.020.23 ± 0.040.25 ± 0.050.17 ± 0.02
Epinephrine (pmol/l)300 ± 55*<109†775 ± 175257 ± 44
Norepinephrine (nmol/l)0.92 ± 0.14*§0.89 ± 0.081.24 ± 0.111.27 ± 0.19
Glucose endoRa(mmol · kg−1 · min−1)0.10 ± 0.010.10 ± 0.010.12 ± 0.010.12 ± 0.01
Glucose Rd(mmol · kg−1 · min−1)0.11 ± 0.010.11 ± 0.010.12 ± 0.010.12 ± 0.01
Fasting plasma glucose–to–insulin ratio100 ± 11§107 ± 13105 ± 1844 ± 3.6
HOMA-IR11.4 ± 1.74.9 ± 0.57.7 ± 1.111.5 ± 0.9
QUICKI0.47 ± 0.02*0.31 ± 0.010.30 ± 0.010.34 ± 0.07
  • Data are means ± SE. Data from 12-week-old, 5-h-fasted C57BL/6J (BL6), 129X1/SvJ (129), FVB/NJ (FVB), and DBA/2J (DBA) male mice. Body weight, blood glucose, insulin, fasting glucose–to–insulin ratio, HOMA-IR, and QUICKI were compiled from basal samples during hyperinsulinemic-euglycemic (euglycemic), insulin-induced hypoglycemic (hypoglycemic), and hyperglycemic clamp experiments in chronically catheterized, conscious mice (n = 27 for BL6; 25 for 129; 22 for FVB; and 24 for DBA mice). QUICKI and HOMA-IR were calculated using equations described in research design and methods. Epinephrine and norepineprhine were measured before hypoglycemic and hyperglycemic clamps (n = 19 for BL6; 18 for 129; 15 for FVB; and 14 for DBA mice). Muscle mass, fat mass, glucagon, and corticosterone were measured before hypoglycemic clamps (n = 8 for BL6; 7 for 129; 7 for FVB; and 7 for DBA mice). EndoRa, Rd, and plasma glucose were determined from euglycemic clamp data (n = 8 for BL6; 9 for 129; 7 for FVB; and 10 for DBA mice). Comparisons are

  • *

    * BL6 vs. FVB,

  • 129 vs. FVB,

  • BL6 vs. 129,

  • §

    § BL6 vs. DBA,

  • 129 vs. DBA, and

  • FVB vs. DBA, where statistical significance is established at P < 0.05.