Naloxone-reversible and non-reversible shock-induced analgesia during development.
We evaluated the development of naloxone-reversible and naloxone-non-reversible analgesia induced by footshock in rats of different ages and correlated it with the concentrations of beta-endorphin and dynorphin in brain areas and the spinal cord. We observed that naloxone-non-reversible shock-induced analgesia appeared first and its appearance might be related to the early presence of high dynorphin concentrations in the spinal cord. Naloxone-reversible analgesia appeared later together with the reaching of adult concentrations of cerebral beta-endorphin.
Panerai
A E
AE
Sacerdote
P
P
Spampinato
S
S
Candeletti
S
S
Ferri
S
S
Mantegazza
P
P
D000698:Analgesia; D000818:Animals; D002490:Central Nervous System / Q000503:physiopathology*; D004399:Dynorphins / Q000502:physiology; D004597:Electroshock; D004723:Endorphins / Q000502:physiology; D004744:Enkephalin, Methionine / Q000502:physiology; D008297:Male; D009270:Naloxone; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D001615:beta-Endorphin
D004723:Endorphins; D009270:Naloxone; D004744:Enkephalin, Methionine; D001615:beta-Endorphin; D004399:Dynorphins