Yamamoto Y, Kanazawa T, Shimamura M, Ueki M, Hazato T. Inhibitory effects of spinorphin, a novel endogenous regulator, on chemotaxis, O2- generation, and exocytosis by N-formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated neutrophils.
Biochem Pharmacol 1997;
54:695-701. [PMID:
9310346 DOI:
10.1016/s0006-2952(97)00221-9]
[Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To characterize the inflammatory effect of spinorphin, an endogenous peptide purified from bovine spinal cord, its effects on chemotaxis, O2- generation, and exocytosis by N-formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated human neutrophils (PMNs) in vitro were examined. At 10 microM, spinorphin significantly inhibited chemotaxis by FMLP-stimulated PMNs. Spinorphin at 100 microM also inhibited both O2- generation and exocytosis of beta-glucuronidase and collagenase by FMLP-stimulated PMNs. The mechanisms by which spinorphin inhibits these PMN functions were examined further. Spinorphin markedly suppressed the binding of FML[3H]P to its receptor on PMNs, as observed in a binding assay. However, other neuropeptides that were examined (angiotensin II and substance P) had no effect on FML[3H]P binding, suggesting the possibility that spinorphin plays a specific role in the inhibition of the binding between FMLP and its receptor. The suppression of FMLP binding also caused a decrease of the FMLP-induced intracellular calcium concentration [Ca2+]i, which acts as a second messenger leading to PMN functions. These results suggest that spinorphin may be a new endogenous inflammation-regulatory peptide that modulates the interaction of FMLP with its receptor.
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