Influence of sex on the interaction between dizocilpine (MK-801) pretreatment and acute cold-restraint stress in epilepsy susceptibility in an animal study

Abstract

Background: Stress is a part of our daily life, inducing neurochemical and neurophysiological changes in the central nervous system.

Objective: The present study was designed to investigate the importance of sex differences in the interaction between dizocilpine (MK-801) pretreatment and acute cold-restraint stress (CRS) in pentylenetetrazole (PTZ)-induced seizures in Swiss albino mice.

Methods: A CRS protocol was applied to mice to investigate the interaction between MK-801 pretreatment (30 min before CRS) and stress (followed by PTZ injection) in epilepsy susceptibility. For this purpose, 6 groups were designated: (1) PTZ control group (received only PTZ); (2) stress group (received stress and PTZ); (3) saline group (received saline and PTZ); (4) MK-801 group (received MK-801 and PTZ); (5) saline + stress group (received saline, stress, and PTZ); and (6) MK-801 + stress group (received MK-801, stress, and PTZ).

Results: Pretreatment with MK-801 (0.125, 0.25, 0.50 mg/kg) significantly potentiated the protective effect of stress in PTZ-induced (65 mg/kg) seizures in both sexes by prolonging the onset of myoclonic jerks and clonic convulsions. Male mice had a significantly greater delay in the onset of myoclonic jerks (males, 66.7-295.5 sec; females, 54.0-247.5 sec; P < 0.05) and clonic convulsions (males, 123.5-789.8 sec; females, 94.5-757.2 sec; P < 0.05) compared with female mice in all groups (ie, PTZ control, stress, saline, MK-801, saline + stress, and MK-801 + stress groups).

Conclusion: The findings of this study in mice suggest the involvement of sex hormones in the interaction between MK-801 pretreatment and acute CRS in PTZ-induced seizures.