TABLE 1.

Plasma GLP-1 levels are similar in wild type and GIP/DT mice

Wild type (WT) and GIP/DT mice (DT) maintained on standard chow (Chow) or high fat (HF) food were fasted for 16 h. Blood was then collected before (fasting) or 15 min after oral administration of glucose (Glc; 6 mg/g body weight) or glucose plus intralipid (Glc/Lipid; 3 mg of glucose plus 4.5 μl of 20% intralipid per gram of body weight). Plasma was assayed for active GLP-1 or insulin by enzyme-linked immunosorbent assay. Note that plasma GLP-1 levels in the GIP/DT mice are similar to or higher than those in nearly all groups of similarly treated wild-type mice and high fat feeding results in elevated GLP-1 levels.

Treatment	GLP-1			Insulin
	Fasting	Glc	Glc/lipid	Fasting	Glc	Glc/lipid
		pm			ng/ml
WT/Chow (n = 12)	≤0.9a	2.4 ± 0.5	2.0 ± 0.3	0.40 ± 0.07	1.47 ± 0.20	1.41 ± 0.24
DT/Chow (n = 10)	≤1.5a	2.7 ± 0.5	3.5 ± 0.5	0.33 ± 0.07	0.43 ± 0.04	0.47 ± 0.21
WT/HF (n = 4-9)	3.1 ± 0.7	1.1 ± 1.6	7.5 ± 3.7	NDb	ND	ND
DT/HF (n = 3-8)	3.6 ± 0.7	5.5 ± 0.9	6.7 ± 3.2	ND	ND	ND

^aIn these groups, GLP-1 levels were below the limits of detection in 5 of 12 wild-type and 3 of 10 GIP/DT animals. Thus, values representing the lowest limit of detectable GLP-1 in the assay were used to estimate maximum average GLP-1 levels for these animals.

^bND, not done.