SEIZURE-PROTECTING EFFECTS OF KYOTORPHIN AND RELATED PEPTIDES IN AN ANIMAL-MODEL OF EPILEPSY

Administration of peptides kyotorphin (KT), neokyotorphin (NKT), and d -ser-2-NKT into the lateral brain ventricle (10 nmol) increased the la tency and attenuated the severity of picrotoxin-induced convulsions in rats. Anticonvulsive effects of the peptides were also observed after their administration into the CA1 hippocampi (2.5, 5, 10 nmol), with the order of potency d-ser-P-NKT --> NKT --> KT. When injected into th e substantia nigra reticulata, the 10 nmol dose of NKT and d-ser-2-NKT displayed equal seizure-protecting effect, which was higher than that for KT. It is concluded that kyotorphin and its analogs provide struc ture-dependent, dose-dependent, and target site-dependent antiepilepti c effect.