The effect of hypoglycemia on the functional and pathological outcome of the newborn rat.

摘要

Controversy remains about the contribution of hypoglycemia to brain damage in the newborn. Therefore, the objective of this study was to determine the effects of isolated hypoglycemia on damage to the immature rat brain. Seven-day-old rats, equivalent to a late preterm human newborn, were placed in either Sham or hypoglycemic groups. Hypoglycemia was induced by insulin infusion for variable periods of time. Outcomes were assessed by behavioral, neurochemical and neuropathologic determination. Rats were categorized as having mild, moderate, or severe hypoglycemia. Behavioral tests revealed no abnormality in hypoglycemic animals. Floro-JadeB showed significant damage in the thalamic reticular nucleus (TRN) of the severe hypoglycemic animals at PD9. However, neuronal (Neu-N), astrocytic (GFAP), and myelin (MBP) staining at PD21 showed no brain injury. There was a significant rise in aspartate and arginine, and drop in glutamine and alanine of hypoglycemic brains. Oxidative stress markers were also increased in hypoglycemic brains. We conclude that isolated prolonged severe hypoglycemia caused a transient, region specific increase in neuronal cell death within the TRN. Though transient in nature, the associated neurochemical alterations warrant further research to determine if more subtle long-term effects may result.