Effect of hepatic glucose production on acute insulin resistance induced by lipid-infusion in awake rats

Table 1 General characteristics of control and lipid-infusion rats (n = 12, mean ± SE)

Group	Control	Lipid-infusion
Body mass (g)	279 ± 19	286 ± 17
Fasting blood glucose (mmol/L)	5.2 ± 0.1	5.1 ± 0.2
Fasting plasma insulin (mU/L)	30.3 ± 2.4	27.9 ± 2.2
Fasting free fatty acids (μmol/L)	672.5 ± 92.2	741.9 ± 50.6

Table 2 Plasma parameters and glucose turnover data in control and lipid-infusion rats during euglycemic hyperinsulinemic claming (mean ± SE)

Group	Basal	Clamping time (min)
		120	200	220	230	240
			Glucose (mmol/L)
Control (n = 12)	5.2 ± 0.1	5.3 ± 0.1	5.0 ± 0.2	5.2 ± 0.1	5.2 ± 0.2	5.4 ± 0.2
Lipid (n = 12)	5.1 ± 0.2	5.3 ± 0.2	5.2 ± 0.2	5.3 ± 0.2	5.5 ± 0.2	5.5 ± 0.2
			FFA (μmol/L)
Control (n = 12)	672.5 ± 92.2	642.3 ± 104.8	240.6 ± 20.9	221.3 ± 27.4	201.8 ± 29.8	183.1 ± 21.4
Lipid (n = 12)	741.9 ± 50.6	2807.2 ± 348.8bd	3086.9 ± 495.2bd	2518.8 ± 416.7bd	2241.2 ± 431.0bd	2346.4 ± 238.5bd
			Insulin (mU/L)
Control (n = 12)	30.3 ± 2.4	34.7 ± 6.4	89.5 ± 7.9	90.7 ± 7.4	88.3 ± 5.9	101.3 ± 6.3
Lipid (n = 12)	27.9 ± 2.2	31.4 ± 3.3	84.2 ± 6.7	93.3 ± 8.9	103.5 ± 16.3	104.5 ± 14.8
			GIR (mg/kg· min)
Controls (n = 12)	0		32.8 ± 1.7	34.4 ± 1.6	34.4 ± 1.6	34.7 ± 1.7
Lipid (n = 12)	0		12.7 ± 1.3b	12.9 ± 1.6b	12.9 ± 1.8b	12.0 ± 1.9b
			GRd (mg/kg·min)
Controls (n = 12)		19.0 ± 4.5	43.1 ± 6.1d	40.1 ± 6.7d	35.5 ± 6.8d	33.2 ± 3.2d
Lipid (n = 12)		18.7 ± 3.0	36.3 ± 3.1d	38.3 ± 4.4d	32.4 ± 4.5d	35.1 ± 3.9d
			HGP (mg/kg·min)
Controls (n = 12)		19.0 ± 4.5	14.2 ± 4.9c	10.2 ± 4.4d	3.1 ± 1.9d	2.3 ± 0.9d
Lipid (n = 12)		18.7 ± 3.0	23.4 ± 4.3bc	25.3 ± 3.7bd	21.5 ± 3.5b	23.2 ± 3.1bd

FFA: Free fatty acids. GIR: Glucose infusion rate. GRd: Glucose disappearance rate. HGP: Hepatic glucose production. ^aP < 0.05;

^bP < 0.01 vs control;

^cP < 0.05;

^dP < 0.01 vs Basal. The basal values of HGP were determined at 120 min.