The strong effects of bilirubin on various levels of the immune system are multifactorial. Concerning the mechanisms of these effects, we hypothesize that the primary causes of the described actions of bilirubin are the direct interaction of bilirubin molecules with cell membranes.

• MeSH
• Bilirubin immunology   pharmacology   MeSH
• Immunosuppressive Agents pharmacology   MeSH
• Humans MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Bilirubin MeSH
• Immunosuppressive Agents MeSH

The effect of an i.p. application of bilirubin on phagocytic activity and the arrangement of the microtubule system of murine peritoneal macrophages were examined. A significant increase of phagocytic activity was observed 3 h after bilirubin treatment, and normal value were reached after 3 d. The increase of the extent of the microtubule system was comparable with that of enhanced phagocytosis but normal values were observed after 1 d.

• MeSH
• Bilirubin pharmacology   MeSH
• Phagocytosis drug effects   MeSH
• Macrophages drug effects   physiology   MeSH
• Microtubules drug effects   metabolism   physiology   MeSH
• Mice, Inbred BALB C MeSH
• Mice MeSH
• Peritoneal Cavity cytology   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Bilirubin MeSH

An in vitro degradation of bilirubin by isolated human granulocytes and lymphocytes is described. Changes in the bilirubin concentration during interaction with these cells were determined spectrophotometrically. The dependence of the reaction velocity on the original bilirubin concentration followed an adsorption isotherm, typical of enzyme processes with a Km of 79 microM at a cell concentration of 500/microL. The primary event is the adsorption of bilirubin to the cell surface and, in addition, its detoxication. Cyanide and sonic treatment of cells inhibit the reaction, salicylic acid enhances the cell activity. The bilirubin-detoxicating effect is discussed with respect to the therapy of hyperbilirubinaemia in neonates.

• MeSH
• Bilirubin metabolism   MeSH
• Granulocytes drug effects   immunology   MeSH
• Potassium Cyanide pharmacology   MeSH
• Humans MeSH
• Lymphocytes drug effects   immunology   MeSH
• Serum Albumin, Bovine metabolism   MeSH
• Temperature MeSH
• Ultrasonics MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Bilirubin MeSH
• Potassium Cyanide MeSH
• Serum Albumin, Bovine MeSH

Using an in vitro phagocytic assay with synthetic 2-hydroxyethylmethacrylate copolymer particles, the phagocytic activity of leukocytes of bilirubin-treated mice (85 and 170 mumol/L in 0.5 mL intraperitoneally) was studied. Bilirubin treatment significantly stimulated the phagocytosis of both peripheral blood granulocytes and monocytes; the increase of phagocytosis persisted for 6 h after bilirubin injection. The potential immunostimulating and/or immunotoxic effect of bilirubin is discussed.

• MeSH
• Bilirubin pharmacology   MeSH
• Time Factors MeSH
• Endotoxins blood   MeSH
• Phagocytosis drug effects   MeSH
• Granulocytes drug effects   physiology   MeSH
• Monocytes drug effects   physiology   MeSH
• Mice, Inbred BALB C MeSH
• Mice MeSH
• Serum Albumin pharmacology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Bilirubin MeSH
• Endotoxins MeSH
• Serum Albumin MeSH

The effect of bilirubin on the phagocytic activity of mouse peritoneal macrophages and on the expression of Fc receptors and receptors for SRBC was studied. Intraperitoneally administered bilirubin influenced the expression of Fc receptors for IgM, IgG2B, IgA and IgE, whereas the expression of other receptors as well as the phagocytic activity of peritoneal macrophages remained unchanged. The possible mechanism of the effect of bilirubin on Fc receptors is discussed.

• MeSH
• Bilirubin pharmacology   MeSH
• Phagocytosis drug effects   MeSH
• Macrophages drug effects   immunology   MeSH
• Mice, Inbred BALB C MeSH
• Mice MeSH
• Receptors, Fc drug effects   MeSH
• Rosette Formation MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Bilirubin MeSH
• Receptors, Fc MeSH

Using an in vitro cytotoxicity assay (51Cr-release), it was shown that bilirubin exerts a cytotoxic effect on both adult and newborn human lymphocytes after a 1-d incubation of cells with bilirubin. The effect of bilirubin on human granulocytes was less pronounced; the association of the cytotoxic effect with a functional immunological perturbation of these cells is discussed.

• MeSH
• Bilirubin pharmacology   MeSH
• Adult MeSH
• Fetal Blood cytology   MeSH
• Granulocytes drug effects   MeSH
• Humans MeSH
• Lymphocytes drug effects   MeSH
• Cell Survival drug effects   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Bilirubin MeSH