Neuropeptide regulation of interleukin-1 activities. Capacity of alpha-melanocyte stimulating hormone to inhibit interleukin-1-inducible responses in vivo and in vitro exhibits target cell selectivity.
alpha-Melanocyte stimulating hormone (alpha-MSH), a 13 amino acid neuropeptide produced by the pituitary gland, was found to markedly inhibit the capacity of exogenously administered interleukin-1 (IL-1) to stimulate the enhanced synthesis of acute-phase proteins and induce neutrophilia in vivo. The administration of ACTH or glucocorticosteroids lacked most of these direct IL-1 inhibitory properties. Therefore, in addition to the previously reported antipyretic action of alpha-MSH, this hormone can also inhibit two other known IL-1 sensitive cellular targets in vivo. Further, alpha-MSH was incapable of modifying the comitogenic influence of IL-1 on murine thymocytes or on an IL-1 responsive T-cell line. These findings suggest a target cell specificity to the IL-1 inhibitory activities of alpha-MSH and fail to support the hypothesis that alpha-MSH functions through competitive inhibition of specific cellular receptors for IL-1.
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D003907:Dexamethasone / Q000494:pharmacology; D005334:Fever / Q000503:physiopathology; D006801:Humans; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology*; D051379:Mice; D008809:Mice, Inbred C3H; D008815:Mice, Inbred Strains; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D000685:Serum Amyloid A Protein / Q000096:biosynthesis*
D007375:Interleukin-1; D000685:Serum Amyloid A Protein; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones