The difference in seizure incidences between young and adult rats related to lipid peroxidation after intracortical injection of ferric chloride

Golden N, Darmadipura S, Bagiada NA
Correspondence: Prof Nyoman Golden, nyoman_golden@yahoo.co.id

ABSTRACT
Introduction Clinical studies have shown that the incidence of early post-traumatic seizures is higher in children than in adults. It has been proposed that iron-induced lipid peroxidation plays an important role in the development of epileptogenic foci. This study examined some of the hypothesised reasons for the difference in the incidence of early post-traumatic seizures between children and adults.
Methods 12 young rats and 12 adult rats were randomised into four groups. Groups 1 and 2 were control groups, comprising six young rats and six adult rats, respectively, and they were administered an intracortical injection of saline. Groups 3 and 4 were injury groups, comprising six young rats and six adult rats, respectively, and they were administered an intracortical injection of FeCl₃. All the rats were observed for six hours post-injection for the occurrence of seizures, and were then killed. The injected hemispheres were extirpated and tested for the malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity as indices of oxidative damage.
Results Seizures were observed only in Group 3. Increased MDA levels and decreased SOD activity were observed in Group 3 (ANOVA, p-value is less than 0.001). Increased MDA levels and decreased SOD activity were significantly higher in rats with seizures (Group 3) than in those without seizures (independent t-test, p-value is less than 0.001).
Conclusion Different levels of lipid peroxidation induced by an intracortical ferric chloride injection may account for the different incidence rates of seizures between young and adult rats.

Keywords: early post-traumatic seizures, epileptogenesis, lipid peroxidation
Singapore Med J 2010; 51(2): 105-109