Up-regulation of the membrane-bound efflux pump P-glycoprotein (P-gp) is associated with the phenomenon of multidrug-resistance in pathogenic organisms, including protozoan parasites. In addition, P-gp plays a role in normal physiological processes, however our understanding of these P-gp functions remains limited. In this study we investigated the effects of the P-gp inhibitor GF120918 in Toxo...

Introduction P-glycoprotein (P-gp) expression on activated lymphocytes in systemic lupus erythematosus (SLE) plays a role in active efflux of intracellular drugs, resulting in drug resistance. The role of P-gp-expressing lymphocytes in the pathogenesis of SLE remains unclear. The aim of this study was to determine the importance of P-gp+CD4+ cells in organ manifestations in refractory SLE. Me...

During brain development and blood-brain barrier (BBB) differentiation the expression of P-glycoprotein (P-gp) may complement the protective function of the placental barrier against xenobiotic substances. To establish an immunohistochemical procedure for P-gp detection, different anti-P-gp monoclonal antibodies were first tested on a fibrosarcoma cell line and colonic carcinoma tissue. The pro...

Human P-glycoprotein (P-gp) is an ATP-binding cassette multidrug transporter that confers resistance to a wide range of chemotherapeutic agents in cancer cells by active efflux of the drugs from cells. P-gp also plays a key role in limiting oral absorption and brain penetration and in facilitating biliary and renal elimination of structurally diverse drugs. Thus, identification of drugs or new ...

Background Positron emission tomography (PET) with the radiolabelled substrate of the multidrug efflux transporter Pglycoprotein (P-gp) (R)-[C]verapamil (VPM) can be used to assess P-gp function at the blood-brain barrier (BBB). We have shown in rats that performing VPM PET scans after half-maximum inhibition of P-gp with the third-generation P-gp inhibitor tariquidar (TQD) is more sensitive fo...

Background The radiolabelled inhibitor of the multidrug efflux transporter P-glycoprotein (P-gp) [C]elacridar was developed as a positron emission tomography (PET) tracer to assess expression levels of P-gp at the blood-brain barrier (BBB) [1]. [C]Elacridar was shown to interact specifically with P-gp at the rodent BBB, but its brain PET signal was very low, which was possibly caused by transpo...

Apoptotic resistance is the main obstacle for treating cancer patients with chemotherapeutic drugs. Multidrug resistance (MDR) is often characterized by the expression of P-glycoprotein (P-gp), a 170-KD ATP-dependent drug efflux protein. Functional P-gp can confer resistance to activate caspase-8 and -3 dependent apoptosis induced by a range of different stimuli, including tumor necrosis and ch...

The activity of cytochrome p450 isozyme 3A4 (CYP3A4) enzyme and P-glycoprotein (P-gp) is modulated by grapefruit juice and herbal drugs. CYP3A4 is the major phase I drug metabolizing enzyme and P-gp is an ATP-dependent drug efflux pump that regulates the intestinal absorption of orally administered drugs. Honey is commonly consumed as a dietary supplement. However, its influence on human CY...

During endotoxemia, the ATP-dependent drug efflux pump P-glycoprotein (Abcb1/P-gp) is upregulated in kidney proximal tubule epithelial cells. The signaling pathway through which lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-alpha) regulates P-gp expression and activity was investigated further in the present study. Exposure of rat kidney proximal tubule cells to TNF-alpha alone o...