Fig. 4: GIP stimulates fatty acid uptake in primary adipocytes in vitro and in adipose tissue in vivo and is inhibited by muGIPR-Ab.

a FA uptake rate in primary differentiated mouse pre-adipocytes treated with GIP for 30 mins then FA uptake rate measured. Data represent mean ± SEM of adipocytes from four mice, three wells/treatment/mouse; Student’s paired t test, *p = 0.023. b FA uptake rate in primary differentiated mouse pre-adipocytes pre-treated with muGIPR-Ab or vehicle overnight then treatment with 10 nM GIP for 30 mins and FA uptake rate measured. Data represent mean ± SEM of adipocytes from three mice, three wells/treatment/mouse. c–i DIO mice were pre-treated with vehicle or muGIPR-Ab (25 mg/kg) for 24 h then injected with saline or DA-GIP and simultaneously oral gavaged with ¹⁴C-oleic acid in olive oil to assess FA uptake. c Plasma insulin measured over time, *p = 0.038 and ****p ≤ 0.0001. Radioactivity uptake into metabolically relevant tissues was measured at necropsy 180 min post-dose in d scWAT, e eWAT, f liver, g skeletal muscle, h brown adipose tissue, and i heart. d Vehicle vs. DA-GIP *p = 0.023 and Vehicle vs. muGIPR-Ab/DA-GIP *p = 0.043, f *p = 0.050. n = 8 mice/group; c two-way repeated measures ANOVA with Tukey’s test for multiple comparisons (c) or (d–i) one-way ANOVA with Tukey’s test for multiple comparisons test, *p ≤ 0.05 and ****p ≤ 0.0001. Data are presented as mean values ± SEM.