Effects of chronic administration of PL017 and beta-funaltrexamine hydrochloride on susceptibility of kainic acid-induced seizures in rats.
There is evidence that 5-7 d after acute seizure episodes induced by kainic acid (KA) the rats develop a long-lasting increase in the susceptibility to seizures followed by spontaneous recurrent seizures (SRS). The present study was focused on the role of hippocampal mu opioid receptors (MORs) in the susceptibility of rats to seizures with the KA model of epilepsy. The rats received a convulsant dose of KA (10 mg/kg, i.p.) were continuously infused with a selective MOR agonist PL017 (2.09, 2.59, 3.29 microg/microl), or a selective MOR antagonist beta-funaltrexamine hydrochloride (beta-FNA, 0.88, 1.10, and 1.35 microg/microl) into ventral hippocampus by means of mini-osmotic pumps. Seven days later, the susceptibility of rats to seizures was checked by a subconvulsant dose of KA (5 mg/kg, i.p.). PL017 infusion shortened the latency and increased the stage of seizures induced by subconvulsant dose of KA in a dose-dependent manner. In contrast, infusion of beta-FNA exhibited a dose-dependent effect against seizures challenged by subconvulsant dose of KA. These results indicate that hippocampal MOR may exert a promoting effect on the susceptibility of rats to KA-induced seizures.
Department of Neurology, PLA 210 Hospital, Dalian 116021, China. liuh2002@hotmail.com
Hui
H
Liu
Hui-Ming
HM
Gao
Wan-Qin
WQ
Zhang
Yi-Yuan
YY
Tang
He-Shan
HS
Song
D000818:Animals; D004198:Disease Susceptibility; D004399:Dynorphins / Q000494:pharmacology*; D004827:Epilepsy / Q000139:chemically induced / Q000503:physiopathology*; D006624:Hippocampus / Q000503:physiopathology*; D007608:Kainic Acid; D008297:Male; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*
C043467:PL017-dynorphin A (6-17); D010446:Peptide Fragments; D017450:Receptors, Opioid, mu; D009271:Naltrexone; C024524:beta-funaltrexamine; D004399:Dynorphins; D007608:Kainic Acid