Type 2 diabetes mellitus facilitates status epilepticus in adult rats: Seizure severity, neurodegeneration, and oxidative stress

Abstract

Abstract Objective The goal of this research was to evaluate the effect of DM type 2 (DM2) on SE severity, neurodegeneration, and brain oxidative stress (OS) secondary to seizures. Methods DM2 was induced in postnatal day (P) 3 male rat pups by injecting streptozocin (STZ) 100 mg/kg; control rats were injected with citrate buffer as vehicle. At P90, SE was induced by the lithium–pilocarpine administration and seizure latency, frequency, and severity were evaluated. Neurodegeneration was assessed 24 h after SE by Fluoro‐Jade B (F‐JB) staining, whereas OS was estimated by measuring lipid peroxidation and reactive oxygen species (ROS). Results DM2 rats showed an increase in latency to the first generalized seizure and SE onset, had a higher number and a longer duration of seizures, and displayed a larger neurodegeneration in the hippocampus (CA3, CA1, dentate gyrus, and hilus), the piriform cortex, the dorsomedial nucleus of the thalamus and the cortical amygdala. Our results also show that only SE, neither DM2 nor the combination of DM2 with SE, caused the increase in ROS and brain lipid peroxidation. Significance DM2 causes higher seizure severity and neurodegeneration but did not exacerbate SE‐induced OS under these conditions. Plain Language Summary Our research performed in animal models suggests that type 2 diabetes mellitus (DM2) may be a risk factor for causing higher seizure severity and seizure‐induced neuron cell death. However, even when long‐term seizures promote an imbalance between brain pro‐oxidants and antioxidants, DM2 does not exacerbate that disproportion.

Keywords

• hyperglycemia
• oxidative stress
• seizures
• status epilepticus
• streptozocin