title: Low density lipoprotein (LDL) inhibits histamine release from human mast cells.
abstract: We examined the effect of low density lipoprotein (LDL) on histamine release from purified human lung mast cells. LDL inhibited anti-IgE- induced histamine release in a dose-dependent manner, with 100 micrograms/ml LDL-protein inhibiting histamine release by 53 +/- 8% (mean +/- SEM); half-maximal inhibition occurred at 40-80 micrograms/ml. LDL also inhibited calcium ionophore A23187-induced histamine release in a dose-dependent manner, with 1 mg/ml of LDL inhibiting histamine release by 83 +/- 9%; half maximal inhibition occurred at 220-280 micrograms/ml. Inhibition by LDL was time-dependent: half-maximal inhibition of anti-IgE- induced histamine release by LDL occurred at 30-50 minutes of incubation. The inhibitory effect of LDL was independent of buffer calcium concentrations (0-5 mM) or temperature (0-37 degrees C). These data are consistent with a newly defined immunoregulatory role for LDL.
mesh_terms: D000001:Calcimycin / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008077:Lipoproteins, LDL / Q000097:blood* / Q000502:physiology; D008407:Mast Cells / Q000502:physiology*
chemical_list: D008077:Lipoproteins, LDL; D000001:Calcimycin