Involvement of thyrotropin-releasing hormone (TRH) neural system of the brain in pentylenetetrazol-induced seizures.
In order to study the relationship between pentylenetetrazol (PTZ)-induced seizures and the thyrotropin-releasing hormone (TRH) neural system, immunoreactive TRH (IR-TRH) and TRH receptor binding activity were determined in discrete regions of the rat brain before as well as 40 s (immediately before seizures), 150 s (during seizures) and 24 h after an intraperitoneal injection of PTZ (75 mg/kg). IR-TRH markedly increased in the septum 40 and 150 s after the injection, and also in the hippocampus and the thalamus-midbrain region 40 and 150 s after the injection, respectively. However, no significant changes were observed in the TRH receptor binding before, during or after the seizures, suggesting that the increased IR-TRH was not released into the synaptic cleft. This speculation was supported by the dose-dependent inhibition of PTZ-induced generalized seizures by the pre-treatment with TRH or its analogue DN-1417 into the cerebral ventricle.
D000818:Animals; D000927:Anticonvulsants; D001921:Brain / Q000503:physiopathology*; D008297:Male; D010433:Pentylenetetrazole / Q000037:antagonists & inhibitors; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018025:Receptors, Thyrotropin-Releasing Hormone; D012640:Seizures / Q000139:chemically induced / Q000503:physiopathology*; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*
D000927:Anticonvulsants; D011956:Receptors, Cell Surface; D018025:Receptors, Thyrotropin-Releasing Hormone; D013973:Thyrotropin-Releasing Hormone; C029762:DN 1417; D010433:Pentylenetetrazole