TABLE 1

Plasma metabolite arterial concentrations obtained under basal state or during an isoglycemic clamp from lean and obese Zucker rats

Lean
Obese
ControlAICARInsulinControlAICARInsulin
Glucose (mmol/l)Basal7.0 ± 0.26.8 ± 0.16.9 ± 0.28.1 ± 0.2*8.2 ± 0.2*8.6 ± 0.2*
Clamp7.0 ± 0.16.9 ± 0.16.7 ± 0.18.3 ± 0.2*7.6 ± 0.1*8.4 ± 0.2*
Insulin (pmol/l)Basal238 ± 57156 ± 24167 ± 351189 ± 166*895 ± 11*1008 ± 127*
Clamp290 ± 48136 ± 48380 ± 601032 ± 158*167 ± 741224 ± 165*
Fatty acids (mmol/l)Basal0.46 ± 0.070.50 ± 0.080.59 ± 0.121.72 ± 0.47*1.59 ± 0.37*1.84 ± 0.34*
Clamp0.38 ± 0.070.11 ± 0.020.34 ± 0.081.71 ± 0.26*0.28 ± 0.091.06 ± 0.19*
Glycerol (mmol/l)Basal0.21 ± 0.020.24 ± 0.020.22 ± 0.030.56 ± 0.08*0.55 ± 0.07*0.65 ± 0.09*
Clamp0.23 ± 0.030.38 ± 0.05§0.21 ± 0.040.61 ± 0.06*0.34 ± 0.02§0.69 ± 0.12*
Triglycerides (mg/dl)Basal43.8 ± 7.332.7 ± 5.225.1 ± 4.597.7 ± 14.8*117.1 ± 20.2*89.3 ± 15.8*
Clamp33.5 ± 9.121.1 ± 4.224.7 ± 3.896.1 ± 24.220.8 ± 3.864.6 ± 17.6
Lactate (mmol/l)Basal0.55 ± 0.040.57 ± 0.030.63 ± 0.041.10 ± 0.16*1.21 ± 0.21*1.30 ± 0.14*
Clamp0.60 ± 0.0313.20 ± 0.380.90 ± 0.061.03 ± 0.0512.00 ± 0.531.51 ± 0.13
  •  Data are means ± SE; n = 7–10 in each group. Rats were infused either with isotonic saline (control), AICAR (bolus, 100 mg/kg body wt; constant, 10 mg · kg−1 body wt · min−1) or insulin (4 mU · kg−1 min−1).

  • *

    * Significantly different from lean littermates undergoing the same treatment (P < 0.01);

  • significantly different from control and insulin-infused groups at same time interval (P < 0.01);

  • significantly different from control infused group at same time interval (P < 0.05);

  • §

    § clamp value is significantly different from basal (P < 0.05);

  • clamp value significantly different from basal (P < 0.01).