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Tryptophan consumption and indoleamines production by peritoneal cavity macrophages
Author(s) -
Martins E.,
Ferreira A. C. F.,
Skorupa A. L.,
Afeche S. C.,
CipollaNeto J.,
Costa Rosa L. F. B. P.
Publication year - 2004
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.1203614
Subject(s) - melatonin , lipopolysaccharide , biology , serotonin , tryptophan , peritoneal cavity , endocrinology , medicine , immune system , incubation , interferon gamma , immunology , biochemistry , receptor , amino acid , anatomy
Melatonin has been shown to regulate several immune functions, and some authors showed that leukocytes are also able to produce the indolamine. In fact, it seems to take part in some immunoregulatory axis, including that related to interferon (IFN) production. So, we evaluated the rate of tryptophan consumption and melatonin and serotonin production in peritoneal cavity‐isolated macrophages and the effect of IFN‐α and ‐γ, lipopolysaccharide (LPS), and phorbol myristate acetate (PMA) on such parameters. Our results indicate that macrophages obtained from the peritoneal cavity of normal rats when incubated with tryptophan show an increase in arylalkylamine N‐acetyltransferase activity that corresponds to an increased melatonin production, as determined in the incubation medium. This process is regulated by IFN‐α and ‐γ, PMA, LPS, and the serum from tumor‐bearing rats, opening the possibility of speculation about different immunoregulatory loops acting through the balance of melatonin/serotonin production by such cells.