PMID- 7127082
OWN - NLM
STAT- MEDLINE
DCOM- 19821216
LR  - 20190614
IS  - 0006-8993 (Print)
IS  - 0006-8993 (Linking)
VI  - 246
IP  - 1
DP  - 1982 Aug 19
TI  - Systemic morphine blocks the seizures induced by intracerebroventricular (i.c.v.) 
      injections of opiates and opioid peptides.
PG  - 121-6
AB  - Intracerebroventricular (i.c.v.) injections of the endorphins and of morphine in 
      rats produce highly characteristic, naloxone sensitive, electrographic seizures. 
      In contrast, systemic injections of morphine have been shown to exert a marked 
      anticonvulsant effect. The present study demonstrates that systemic morphine 
      pretreatment can prevent the occurrence of electrographic seizures injected by 
      i.c.v. morphine, Leu-enkephalin and beta-endorphin and that the anti-epileptic 
      effect of morphine can be reversed by naloxone. Male albino rats, previously 
      prepared for chronic i.c.v. injections and EEG recordings, were pretreated with 
      0--100 mg/kg of intraperitoneal (i.p.) morphine. Thirty five minutes later 
      morphine (520 nmol), Leu-enkephalin (80 nmol) or beta-endorphin (5 nmol) were 
      injected i.c.v. Pretreatment with i.p. morphine blocked the occurrence of 
      seizures induced by morphine and both endogenous opioids. Lower doses of systemic 
      morphine (50 mg/kg) were necessary to block i.c.v. morphine seizures than the 
      dose (100 mg/kg) necessary to block seizures induced by i.c.v. Leu-enkephalin and 
      beta-endorphin. Naloxone (1 mg/kg) administered 25 min following 50 mg/kg of i.p. 
      morphine and preceding the injections of i.c.v. morphine reversed the 
      antiepileptic effect of systemic morphine. These results demonstrate the possible 
      existence of two opiate sensitive systems, one with excitatory-epileptogenic 
      effects and the other possessing inhibitory-antiepileptic properties. The 
      possible relationship between these findings and the known heterogeneity of 
      opiate receptors and opiate actions is discussed.
FAU - Urca, G
AU  - Urca G
FAU - Frenk, H
AU  - Frenk H
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Brain Res
JT  - Brain research
JID - 0045503
RN  - 0 (Endorphins)
RN  - 0 (Narcotics)
RN  - 36B82AMQ7N (Naloxone)
RN  - 76I7G6D29C (Morphine)
SB  - IM
MH  - Animals
MH  - Endorphins/administration & dosage/*pharmacology
MH  - Injections, Intraventricular
MH  - Male
MH  - Morphine/administration & dosage/*pharmacology
MH  - Naloxone/pharmacology
MH  - Narcotics/administration & dosage/*pharmacology
MH  - Rats
MH  - Rats, Inbred Strains
MH  - Seizures/chemically induced/*drug therapy
EDAT- 1982/08/19 00:00
MHDA- 1982/08/19 00:01
CRDT- 1982/08/19 00:00
PHST- 1982/08/19 00:00 [pubmed]
PHST- 1982/08/19 00:01 [medline]
PHST- 1982/08/19 00:00 [entrez]
AID - 0006-8993(82)90148-2 [pii]
AID - 10.1016/0006-8993(82)90148-2 [doi]
PST - ppublish
SO  - Brain Res. 1982 Aug 19;246(1):121-6. doi: 10.1016/0006-8993(82)90148-2.