Effects of mammalian FMRF-NH2-related peptides and IgG from antiserum against them on aggression and defeat-induced analgesia in mice.

Abstract

The effects of two endogenous mammalian FMRFamide (Phe-Met-Arg-Phe-NH2)-related peptides, an octapeptide F8Fa (Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2) and an octadecapeptide A18Fa (Ala-Gly-Glu-Gly-Leu-Ser-Ser-Pro-Phe-Trp-Ser-Leu-Ala-Pro-Gln-Arg-Phe-NH2 ), and IgG from serum against them on the responses to aggression and defeat-induced analgesia were examined in subordinate mice in "resident-intruder" pairings. Intracerebroventricular (ICV) administrations of F8Fa and A18Fa (0.10-10 micrograms) reduced, in a dose-dependent manner, the number of bites to obtain defeat in the subordinate mice during the agonistic encounters, as well as attenuating defeat-induced analgesia, with F8Fa having a greater inhibitory effect than A18Fa. Peripheral administration of naloxone (1.0 mg/kg) had a similar inhibitory effect on the number of bites to defeat and the level of defeat-induced analgesia. In contrast, ICV administrations of F8Fa-IgG and A18Fa-IgG antisera increased the number of bites to defeat and augmented the levels of defeat-induced analgesia, with F8Fa-IgG having a greater effect than A18Fa-IgG. These results provide further evidence that the peptides, F8Fa and A18Fa, are involved in the modulation of opioid-mediated analgesia accompanying biological stressors and suggest that these endogenous FMRF-NH2-related peptides may also be associated with the expression of opioid-sensitive components of aggressive behavior.

• Authors: M Kavaliers, H Y Yang
• Journal: Peptides (Peptides) 1991 Mar-Apr Vol. 12 Issue 2 Pg. 235-9 ISSN: 0196-9781 [Print] United States
• PMID: 2067975 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Immunoglobulin G
• Neuropeptides
• Oligopeptides
• FMRFamide
• phenylalanyl-leucyl-phenylalanyl-glutaminyl-prolyl-glutaminyl-arginyl-phenylalaninamide
• A18Famide

Topics

• Aggression (drug effects, physiology)
• Amino Acid Sequence
• Analgesia
• Animals
• FMRFamide
• Immunoglobulin G (pharmacology)
• Male
• Mice
• Molecular Sequence Data
• Neuropeptides (antagonists & inhibitors, pharmacology, physiology)
• Nociceptors (drug effects, physiology)
• Oligopeptides (chemistry, pharmacology, physiology)