INFLUENCE OF ORCHIECTOMY AND OVARIECTOMY ON THE BLOOD-BRAIN-BARRIER PERMEABILITY DURING BICUCULLINE-INDUCED SEIZURES

The changes in the permeability of the blood-brain barrier (BBB) durin g bicuculline-induced seizures were investigated in ovariectomized fem ale and orchidectomized male rats. The rats were anesthetized with die thyl ether. Evans blue, which was used as a BBB tracer, was injected i nto femoral vein 5 min before administering bicuculline to induce gran dmal seizures. Ten groups of rats were studied: Group I: control femal e; Group II: control male; Group III: intact female + bicuculline; Gro up IV: intact male + bicuculline; Group V: ovariectomized female; Grou p VI: orchidectomized male; Group VII: ovariectomized female + bicucul line; Group VIII: orchidectomized male + bicuculline (1.2 mg/kg, i.v.) ; Group IX: ovariectomized female + estrogen + bicuculline; Group X: o rchidectomized male + estrogen + bicuculline. Adult male and female ra ts were orchidectomized and ovariectomized 3 weeks before the experime nts, or sham operated under general anesthesia. During bicucculline-in duced seizures, the mean arterial blood pressure increased significant ly in both intact and ovariectomized and orchidectomized rats. BBB les ions were present in 80 percent of intact female rats and 50 percent o f ovariectomized rats after bicuculline-induced seizures. This differe nce between intact and ovariectomized rats was found to be significant (p < 0.01). There was no statistically significant change in the BBB permeability between intact and orchidectomized rats after convulsion. Generating seizures in both ovariectomized and orchidectomised rats, after administrating of estrogen, did not lead to any significant alte ration in BBB permeability. Our results suggest that the extravasation of Evans blue albumin was most pronounced in the brain of intact fema le rats when compared to ovariectomized rats after bicuculline-induced seizures. After administrating estrogen, the decreased BBB permeabili ty values of ovariectomised rats could not reach the values in intact rats.