Fig. 3

Gut ghrelin infusion disrupts the gut nutrient sensing-related mechanisms. a Schematic representation of the working hypothesis. Lipid with or without ghrelin, or saline was infused through a duodenal catheter. b Experimental procedure and clamp protocol. c-e Gut lipids infusion increased the GIR (c), and decreased HGP (d and e). When duodenal lipid was co-infused with ghrelin, the effects of lipids on GIR and HGP were abolished. f Glucose uptake was unchanged in all groups. g - i The effect of gut ghrelin on glucose homeostasis during fasting-refeeding. g Schematic representation of the experimental design. A duodenal catheter, the internal jugular vein and carotid artery catheters were implanted on day 1. Rats were subjected to a 40 h fasting from 5 p.m. on day 5 until 9 a.m. on day 7. Ten minutes before the completion of the forty-hour fast, rats were infused with intraduodenal saline or ghrelin (n = 5 per group). Rats were refed on regular chow at time 0 min where food intake and blood glucose were monitored for 20 min. h Plasma glucose levels during refeeding. i Cumulative food intake during refeeding. GIR, glucose infusion rate; HGP, hepatic glucose production. Values are shown as mean ± SEM. *P < 0.05, **P < 0.01 vs. saline or other groups