Inhibition of nociceptin/orphanin FQ on penicillin-induced seizures in rats.
The opioid peptides were thought to be involved in specific types of seizures. Nociceptin/Orphanin FQ (NC) is the endogenous ligand of the nociceptin opioid peptide (NOP) receptor and may play a role in epilepsy. However, accumulated evidences indicated that NC had both anti- and pro-convulsive effects, and the direct effect of NC in modulating epilepsy in the hippocampus still remained unclear. In this study, we investigated the effect of NC on penicillin-induced seizures (PIS) in rats. Seizure model was produced by intra-hippocampus injection of penicillin in anesthetized rats. The electroencephalography (EEG) was then observed and estimated by power spectrum analysis. Pretreatment of NC (intracerebroventricular, i.c.v.) depressed PIS in a dose-dependent manner at doses of 0.055, 0.55 and 5.5 nmol in 2 microl saline, respectively. [Nphe1]Nociceptin(1-13)NH2, a selective NOP receptor antagonist reversed the effect of NC against PIS, and this antagonist was inactive to PIS itself. These results indicated that NC had a receptor-specific preventive effect against PIS.
Feng
Yin
Y
Department of Integrative Medicine and Neurobiology, Institute of Acupuncture Research, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Chao
Dong-Man
DM
Li
Wei-Min
WM
Cao
Yin-Xiang
YX
Wang
Yan-Qing
YQ
Wu
Gen-Cheng
GC
D000818:Animals; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008845:Microinjections; D018847:Opioid Peptides / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010406:Penicillins; D051381:Rats; D017207:Rats, Sprague-Dawley; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism*; D012640:Seizures / Q000139:chemically induced / Q000517:prevention & control*; D000094942:Nociceptin Receptor; D000097629:Nociceptin
D018847:Opioid Peptides; D010406:Penicillins; D011957:Receptors, Opioid; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C000722285:Oprl1 protein, rat