Figure 4.

Blockade of GLP-1 receptor prevents post-VSG hypoglycemia but not glycemic variability after an oral glucose load. (A) Schematic experimental timeline during CGM after surgery. (B–C) Blood glucose levels during 6 h of ad libitum feeding in saline or Ex9-treated sham (B) or VSG (C) rats. (D) Violin plots represent the median, quartiles, minimum, maximum, and distribution of glucose levels during 6 h of the ad libitum feeding condition. (E) The glucose nadir during 2 h of ad libitum feeding ingestion. (F) Mean absolute glucose (MAG) during 6 h of ad libitum feeding. Mean ± SEM (main effect of surgery). (G–H) Blood glucose levels during 120 min after an oral glucose load in saline or Ex9-treated sham (G) or VSG (H) rats. Mean ± SEM. (I) Peak glucose levels after an oral glucose load. Mean ± SEM. Main effect of surgery was observed in both drug groups (main effect of surgery). (J) Glucose nadir after an oral glucose load. Mean ± SEM (main effect of drug). (K–L) Ex9 treatment increased plasma glucagon level but not plasma insulin levels of VSG versus sham rats 15 min after a liquid mixed-meal gavage. *P < 0.05. All data are represented as mean ± SEM except (D). Saline or Ex9 (50 μg per kg average rat BW) was cross-injected to the rats 15 min into the dark phase during ad libitum feeding (B–E) or 15 min prior to oral glucose administration (F–I). Data obtained from the ad libitum feeding condition are represented as an average of 3 consecutive days of measurements. The cross-injection studies were performed at 3–4 weeks, and there was a 4-day washout period. Sham (n = 5), VSG (n = 6). One VSG rat showing low glycemic response under a single oral glucose administration was omitted (F–K).