title: Behavioral and electrographic effects of opioids on kindled seizures in rats.
abstract: Our laboratory previously suggested that opioid peptides are released by an amygdaloid kindled seizure and may affect the elicitation of a subsequent seizure. The present study examined the effects of morphine, naloxone, enkephalin analogues, and conditions of morphine tolerance and withdrawal on the severity and duration of a series of amygdaloid kindled seizures. The results suggest two distinct opiate/opioid actions on seizures. The first is an anticonvulsant effect on the behavioral manifestations of seizures. This effect is seen following a high dose (50 mg/kg) of morphine or a low dose (6 mg/kg) of enkephalin analogue (LY146104), and is reversed by naloxone. The second is a naloxone-reversible prolonging effect of the high dose of morphine on the electrographic components of the seizures. Receptor affinities of these various opiate/opioid drugs suggest that these two actions are mediated by different receptors which appear not to include high affinity mu receptors.
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004361:Drug Tolerance; D004745:Enkephalins / Q000494:pharmacology; D006168:Guinea Pigs; D006801:Humans; D007696:Kindling, Neurologic; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology; D009022:Morphine Derivatives / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012640:Seizures / Q000503:physiopathology*; D013375:Substance Withdrawal Syndrome; D014649:Vas Deferens / Q000187:drug effects
chemical_list: D004745:Enkephalins; D009022:Morphine Derivatives; D009294:Narcotics; D009270:Naloxone; D009020:Morphine; C010616:normorphine