BAM-18: analgesia, hyperalgesia and locomotor effects.

Abstract

BAM-18, a proenkephalin A-derived opioid peptide, is widely distributed throughout rat CNS and displays high affinity for both mu and kappa opioid receptors. In the present study, BAM-18 was tested in two analgesia paradigms, tail-flick and hot-plate. Injections were centrally administered through a chronically implanted unilateral cannula in the lateral ventricle. In the tail-flick, low doses of BAM-18 (5 micrograms) produced a hyperalgesia while high doses of BAM-18 (50 micrograms) produced an analgesic response. Naloxone (10 mg/kg, s.c.) reversed the BAM-18-induced analgesia and unmasked a persistent hyperalgesia. Morphine-induced (1 microgram) analgesia was completely reversed by 5 micrograms BAM-18. In the hot-plate test, high doses of BAM-18 produced analgesia, with no hyperalgesia observed at any dose. Naloxone reversed the BAM-18-induced analgesia. The locomotor effects of BAM-18 did not differ from those of morphine except in effective dose (50 micrograms vs. 5 micrograms, respectively). Opioid and non-opioid effects of BAM-18 are discussed and compared with other endogenous peptides.

• Authors: K E Stevens, F M Leslie, C J Evans, J D Belluzzi, L Stein
• Journal: Neuropeptides (Neuropeptides) Vol. 12 Issue 1 Pg. 21-7 (Jul 1988) ISSN: 0143-4179 [Print] Netherlands
• PMID: 3419557 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Protein Precursors
• BAM 18P
• Enkephalin, Methionine

Topics

• Amino Acid Sequence
• Analgesia
• Animals
• Enkephalin, Methionine (analogs & derivatives, analysis, pharmacology)
• Hyperalgesia (chemically induced)
• Hyperesthesia (chemically induced)
• Injections, Intraventricular
• Locomotion (drug effects)
• Male
• Molecular Sequence Data
• Protein Precursors (analysis, pharmacology)
• Rats
• Rats, Inbred Strains