Nutrient sensing is an important feature of pancreatic islets to manage glucose homeostasis. Islets are highly responsive to glucose yet are significantly less sensitive to individual amino acids. Conversely, combinations of ingested amino acids may augment insulin secretion when given with glucose. We explored the insulinotropic effect of different amino acid combinations when co-administered with low (3 mM) and high (11 m) glucose levels.
Batch incubations were performed with islets from healthy and lean (BMI < 25 kg/m2) Caucasians. Islets were starved at 3 mM glucose before being sequentially treated with amino acids in conjunction with low and high glucose, followed by KCl. Insulin secretion was analysed using ELISA and normalized by islet equivalent (IEQ) counts.
When BCAA is given with low glucose, insulin secretion significantly increases, comparable to high glucose alone. When given with high glucose, BCAA had no insulinotropic effects. Other combinations did not result in a significant increase in insulin secretion at both low and high glucose. In summary, our data examines the insulinotropic effect of different amino acid combinations at high and low glucose respectively, representing fasted and fed states.
K. Hor Cheng: None. J.C.Y. Chan: None.
