background: ulcerative colitis (uc) is a multi-factorial autoimmune disease. p-glycoprotein is encoded by the multidrug resistance 1 (mdr1) gene. the c3435t polymorphism in the mdr1 gene is correlated with low p-glycoprotein expression. additionally, vitamin d has regulatory effects on the immune system. the aim of our study was to determine the association between the c3435t mdr1 polymorphism ...

Continuous use of St. John's wort decreases the bioavailabilities of a variety of drugs. This interaction is attributed to the induction of cytochrome P450 3A4 and/or P-glycoprotein. In this study, we aimed to examine the chronic effects of St. John's wort and its constituents, hyperforin and hypericin, on the expression and function of P-glycoprotein in an intestinal cell line, LS 180. We also...

Verapamil is subject to extensive oxidative metabolism mediated by cytochrome P450 enzymes with less than 5% of an oral dose being excreted unchanged in urine. Furthermore, verapamil is known to be a potent inhibitor of P-glycoprotein function. There is evidence from in vivo investigations that some verapamil metabolites might be actively transported. The aim of the present study was to investi...

P-glycoprotein, the most extensively studied ATP-binding cassette (ABC) transporter, functions as a biological barrier by extruding toxins and xenobiotics out of cells. In vitro and in vivo studies have demonstrated that P-glycoprotein plays a significant role in drug absorption and disposition. Because of its localisation, P-glycoprotein appears to have a greater impact on limiting cellular up...

PURPOSE The retinal pigment epithelium (RPE) is a transporting epithelial monolayer that controls hydration and composition of the subretinal space. P-glycoprotein is an ATP-binding cassette transport protein known to transport a wide range of hydrophobic compounds. The expression of P-glycoprotein in barrier epithelial cells suggests that it could serve a normal protective function, possibly c...

Recombinant human erythropoietin is a glycoprotein hormone that stimulates erythropoiesis. In clonogenic assays of hematopoietic progenitors, high concen-trations of erythropoietin (Epo) increase CFU-E and diminish the number of granulocytes formed per culture plate. Fetal progenitors are more sensitive to these effects of Epo than progenitors from adults. We administered doses 50, 100, 200 IU/...

Dr. Summerfield's present address is Department of Medicine, Royal Free Hospital, London, England. Address reprint requests to Dr. Jones. Received for publication 13 July 1981 and in revised form 15 February 1982. population of these cells. In addition, in vivo studies of the fate of intravenously administered '251-agalactoorosomucoid indicated that its rate of disappearance from plasma, hepati...

fibrillin is a large glycoprotein synthesized in the tissues involved in marfan syndrome, and known to be involved in tissue elasticity. the syndrome is corresponded to fbn1 gene and is characterized by cardiovascular, ocular, and skeletal abnormalities. n-terminus of fibrillin 1 binds to microfibril-associated glycoprotein 1 (magp-1) in a calcium-dependent manner. in this study, the amino acid...

The general hypothesis for the biological function of beta 2-glycoprotein I is that it neutralizes all negatively charged macromolecules that might enter the bloodstream and diminishes unwanted activation of the blood coagulation. In the present study we report that beta 2-glycoprotein I inhibits the activation of the contact phase system of the intrinsic pathway of blood coagulation. Activatio...

Screening of serum by using a surface plasmon resonance analysis assay identified beta2-glycoprotein-I/apolipoprotein H as a plasma component binding to the renal epithelial endocytic receptor megalin. A calcium-dependent megalin-mediated beta2-glycoprotein-I endocytosis was subsequently demonstrated by ligand blotting of rabbit renal cortex and uptake analysis in megalin-expressing cells. Immu...