Inhibition of leukocyte phagocytosis by serotonin and its possible role in tumor cell destruction.
Intraportal tumour cell (TC) injection activates platelets which release serotonin (5-HT). Thrombocytopenia or 5-HT blockade decrease the hepatic lodgement of the injected TCs. A hypothetical explanation of this is 5-HT inhibition of TC killing by phagocytes (e.g. leukocytes and Kupffer cells). In this study, leukocyte phagocytosis was analysed by a chemiluminescence technique at different 5-HT concentrations. Significant inhibition of phagocytosis occurred at 5-HT concentrations of 10(-4) M to 10(-8) M, with maximum inhibition at 10(-4) M. Comparable concentrations of 5-HT may be found locally in the liver during TC infusion, supporting the hypothesis that 5-HT has an inhibitory effect on phagocyte-mediated TC killing.
Nannmark
U
U
Department of Anatomy, University of Göteborg, Sweden.
Sennerby
L
L
Bjursten
L M
LM
Skolnik
G
G
Bagge
U
U
D000818:Animals; D004305:Dose-Response Relationship, Drug; D006801:Humans; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D009504:Neutrophils / Q000187:drug effects*; D010587:Phagocytosis / Q000187:drug effects*; D051381:Rats; D016897:Respiratory Burst / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology*
D012701:Serotonin