![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
FC Tortella, L Robles and HI Mosberg
The opioid receptor types involved in the mediation of enkephalin- induced electroencephalographic (EEG) seizures were studied in unanesthetized, freely moving rats. Four receptor-selective peptide ligands were evaluated for effectiveness in producing nonconvulsive EEG seizures after i.c.v. administration; these included the mu agonist, [D- Ala2-N-methyl-Phe4-Gly5-ol]enkephalin (DAGO), the mixed mu-delta agonist, [D-Ala2-D-Leu5]enkephalin (DADLE), and the selective delta agonists, [D-Pen2-D-Pen5]enkephalin and [D-Pen2-L-Pen5]enkephalin. Only DAGO and DADLE were found to produce EEG seizures, with DAGO being 9 times more potent than DADLE. DAGO produced a greater number of seizure episodes with a greater overall incidence compared with DADLE, reflecting its potent effect to elicit EEG seizure activity in these rats. Injections of [D-Pen2-D-Pen5]enkephalin or [D-Pen2-L- Pen5]enkephalin, even at the highest doses tested, failed to produce seizure activity. Behaviorally, the DAGO and DADLE EEG seizures were nonconvulsive but were temporally associated with episodic bursts of wet-dog shakes. The enkephalin-induced responses were extremely sensitive to antagonism by naloxone and completely blocked by pretreatment with the irreversible mu antagonist beta-funaltrexamine. The selective delta opioid receptor antagonist ICI 174,864 (N,N-diallyl- Tyr-Aib-Aib-Phe-Leu-OH) was ineffective. The use of the most selective agonists and antagonists for mu and delta opioid receptors suggests that, in rats, enkephalin-induced EEG seizures are mediated exclusively by mu opioid receptors and not by delta opioid systems.
This article has been cited by other articles:
|
|
 |
|
  W. J. Meilandt, G.-Q. Yu, J. Chin, E. D. Roberson, J. J. Palop, T. Wu, K. Scearce-Levie, and L. Mucke Enkephalin Elevations Contribute to Neuronal and Behavioral Impairments in a Transgenic Mouse Model of Alzheimer's Disease J. Neurosci., May 7, 2008; 28(19): 5007 - 5017. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A Hofmann, N Tangri, A-L Lafontaine, and R B Postuma Myoclonus as an acute complication of low-dose hydromorphone in multiple system atrophy. J. Neurol. Neurosurg. Psychiatry, August 1, 2006; 77(8): 994 - 995. [Full Text] [PDF]
|
|
|
|
 |
|
 E. H. Sinz, W. A. Kofke, and R. H. Garman Phenytoin, Midazolam, and Naloxone Protect Against Fentanyl-Induced Brain Damage in Rats Anesth. Analg., December 1, 2000; 91(6): 1443 - 1449. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. C. Tortella, J. Rose, L. Robles, J. E. Moreton, J. Hughes, and J. C. Hunter EEG Spectral Analysis of the Neuroprotective Kappa Opioids Enadoline and PD117302 J. Pharmacol. Exp. Ther., July 1, 1997; 282(1): 286 - 293. [Abstract] [Full Text]
|
|
 |
 |
 |
|
 |
 |
 |
