Oral Glutamine Is Superior Than Oral Glucose to Promote Glycemia Recovery in Mice Submitted to Insulin-Induced Hypoglycemia

The effect of the oral administration of blood glucose precursors on glycemia recovery and liver glucose production in fasted mice subjected to insulin-induced hypoglycemia (IIH) was investigated. IIH was obtained with increasing doses (from 0.5 to 2.0 U·kg(−1)) of intraperitoneal regular insulin where glycemia was evaluated from 0 to 300 min after insulin injection. The dose of 1.0 U·kg(−1) showed the best results, that is, a clear glycemia recovery phase without convulsions or deaths. Thus, this dose was used in all experiments. Afterwards, mice submitted to IIH received orally by gavage: saline (control group), glucose (100 mg·kg(−1)), glycerol (100 mg·kg(−1)), lactate (100 mg·kg(−1)), alanine (100 mg·kg(−1)), or glutamine (100 mg·kg(−1)). It was observed that glutamine was more effective in promoting glycemia recovery if compared with glucose, lactate, glycerol, or alanine. In agreement with these results, the best performance in terms of liver glucose production was obtained when glutamine was used as glucose precursors. These results open perspectives for clinical studies to investigate the impact of oral administration of gluconeogenic amino acids to promote glycemia recovery during hypoglycemia.