Table 3.

Arterial plasma GLP-1(7–36) concentration (pmol/L) during portal and jugular vein infusion

	Portal Vein GLP-1 (n = 5)	Jugular Vein GLP-1 (n = 5)	P Value
Baseline	2.6 ± 0.4	3.3 ± 0.9	ns
2.5 μg·kg−1·h−1	14.3 ± 2.4	43.6 ± 5.0***	P < 0.001
5.0 μg·kg−1·h−1	36.6 ± 2.8	80.9 ± 3.4***	P < 0.001

With DPP4 Inhibition (Vildagliptin)
	Portal Vein GLP-1 (n = 5)	Jugular Vein GLP-1 (n = 6)	P Value
Baseline	7.0 ± 2.5	7.7 ± 2.2	ns
2.5 μg·kg−1·h−1	47.1 ± 12.3	116.7 ± 27.9	ns
5.0 μg·kg−1·h−1	184.8 ± 35.7	443.2 ± 66.4**	P < 0.01

Both doses (P < 0.0001) of GLP-1 and infusion site (P < 0.0001) had a significant impact on the arterial plasma GLP-1 levels when analyzed by RM two-way ANOVA. Bonferroni post tests demonstrated significantly higher plasma GLP-1 levels after infusion of both 2.5 and 5 μg/kg/h GLP-1 into the jugular vs. portal vein (P < 0.001 for both doses). With DPP4 inhibition (vildagliptin), both doses (P < 0.0001) of GLP-1 and infusion site (P < 0.0081) had a significant impact on the arterial plasma GLP-1 levels when analyzed by RM two-way ANOVA. Bonferroni post tests demonstrated significantly higher plasma GLP-1 levels after infusion of 5 μg·kg⁻¹·h⁻¹ GLP-1 into the jugular vs. portal vein (P < 0.01). All values are mean ± SE. DPP4, diapeptidylpeptidase 4; GLP-1, glucagon-like peptide-1; ns, not significant; RM, repeated measures.

^**P < 0.01;

^***P < 0.001.