Spinal co-administration of peptide substance P antagonist increases antinociceptive effect of the opioid peptide biphalin.
Intrathecal injection of 0.25 micrograms of undecapeptide substance P antagonist (SPA) produced transient antinociception with a peak effect at 5 min. Increasing the SPA dose resulted in neurotoxicity. Intrathecal injection of the opioid peptide biphalin (BIP) produced antinociception for over 3 hrs without neurotoxicity. Co-administration of SPA (at subtoxic doses) increased BIP's antinociceptive effect. Naltrexone reversed analgesia due to BIP alone as well as after BIP+SPA.
Misterek
K
K
Department of Pharmacodynamics, Medical Academy, Warsaw, Poland.
Maszczynska
I
I
Dorociak
A
A
Gumulka
S W
SW
Carr
D B
DB
Szyfelbein
S K
SK
Lipkowski
A W
AW
D000700:Analgesics / Q000008:administration & dosage* / Q000494:pharmacology; D000818:Animals; D004357:Drug Synergism; D004745:Enkephalins / Q000008:administration & dosage* / Q000494:pharmacology; D007278:Injections, Spinal; D008297:Male; D009271:Naltrexone / Q000494:pharmacology; D010146:Pain / Q000188:drug therapy*; D010147:Pain Measurement; D051381:Rats; D017208:Rats, Wistar; D013373:Substance P / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology
D000700:Analgesics; D004745:Enkephalins; D013373:Substance P; D009271:Naltrexone; C032132:substance P, prolyl(2)-tryptophan(7,9)-; C053673:biphalin