Subject(s)
Analgesics/chemistry , Bone Marrow/chemistry , Oligopeptides , Pain/drug therapy , Peptides/chemistry , Amino Acid Sequence , Amino Acids/analysis , Analgesics/pharmacology , Animals , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Molecular Sequence Data , Peptides/isolation & purification , Peptides/pharmacologyABSTRACT
Bone marrow myelopeptides (MP), besides having immunostimulatory activity, had a pronounced dose-dependent effect on the development of pain sensitivity in mice. Nanogram amounts of MP evoked a hyperalgesic response and increased antibody formation to sheep red blood cells three to nine times. Milligram amounts of MP had a hypoalgesic effect and did not affect antibody response. Opioid peptides derived from the bone marrow MP are involved in the expression of the antibody response, and a mixture of synthetic opioids, corresponding in composition to that found in natural MP, stimulated antibody production. The antibody-stimulating effect of MP was abolished by naloxone. Of the opioid peptides, only beta-endorphin showed antibody-stimulating activity. On reversed-phase chromatography the antibody-stimulating peptides and beta-endorphin were eluted in different fractions, indicating that the immunostimulatory and opioid activities are produced by different peptide molecules.
