INS and Hypoglycemia: However, it should be noted that: (1) the 20 min experimental time window was the maximum we could safely achieve without lethal hypoglycemia caused by anesthesia plus sulfonylurea treatment; (2) the biological half-life of insulin is ~10 min36, meaning that glucose-lowering effects may be present for a short time after cessation of illumination; and (3) sulfonylureas activate non-ionic second messenger pathways (e.g. Epac237, 38) that may display persistent signaling.