INS and type 2 diabetes mellitus: To further confirm the physiological relevance of the allosteric interaction between fasiglifam and endogenous FFAs in vivo, we conducted OGTT in diabetic neonatal streptozotocin (N-STZ)-1.5 rats, a T2DM model with impaired insulin secretion, under treatment with the lipolysis inhibitor acipimox that lowers plasma FFA levels by inhibiting hormone-sensitive lipase.