ABCA1 is a critical regulator of lipid efflux from cells, which is highly regulated at the transcriptional and posttranslational levels. However, cells from different species and different tissues, and primary versus immortalized cells, show different modes of regulation. We have carried out a comparative analysis of basic signaling pathways of lipid efflux in mouse J774 cells, mouse peritoneal...

P-Glycoprotein (P-gp) is an ATP-dependent drug efflux transporter involved in multidrug resistance and drug disposition in many organ systems. A majority of P-gp substrates are lipophilic amine drugs which also exhibit rapid extensive accumulation in lung tissue. P-gp is expressed in lung tissue, and the very nature of this drug efflux mechanism suggests a moderating role in pulmonary drug disp...

BACKGROUND Walnuts significantly decrease total and low-density lipoprotein cholesterol in normo- and hypercholesterolemic individuals. No study to date has evaluated the effects of walnuts on cholesterol efflux, the initial step in reverse cholesterol transport, in macrophage-derived foam cells (MDFC). The present study was conducted to investigate the mechanisms by which walnut oil affects ch...

Several compounds have been identified that display low-efficacy, "partial substrate" activity. Here, we tested the hypothesis that the mechanism of this effect is a slower rate of induced neurotransmitter efflux than that produced by full substrates. Biogenic amine transporter release assays were carried out in rat brain synaptosomes and followed published procedures. [(3)H]1-methyl-4-phenylpy...

OBJECTIVES Does exposure to subinhibitory concentrations of quinolones favour overexpression of efflux pumps or selection of target site mutations? METHODS ATCC 49,619 (fully susceptible) and SP32 (clinical isolate with PmrA-mediated efflux and mutation in ParE) were exposed for 24 h in broth to ciprofloxacin, levofloxacin, moxifloxacin or garenoxacin at concentrations of 0.5x the MIC, with d...

OBJECTIVE To investigate the contribution of gyrA mutation and efflux pumps to fluoroquinolone resistance and multidrug resistance among Escherichia coli isolates from dogs and cats. SAMPLE POPULATION 536 clinical isolates of E coli. PROCEDURES Minimum inhibitory concentrations (MICs) were determined for enrofloxacin and 6 other drug classes by use of broth microdilution techniques. Real-ti...

Abstract. Leading an effective response to the accelerating crisis of anthropogenic climate change will require improved understanding global carbon cycling. A critical source uncertainty in Earth system models (ESMs) is role microbes mediating both formation and decomposition soil organic matter, hence determining patterns CO2 efflux. Traditionally, ESMs model turnover as a first-order process...

Difficult access to 40-m-tall emergent trees in tropical rainforests has resulted in a lack of data related to vertical variations in wood CO2 efflux, even though significant variations in wood CO2 efflux are an important source of errors when estimating whole-tree total wood CO2 efflux. This study aimed to clarify vertical variations in wood CO2 efflux for emergent trees and to document the im...

UNLABELLED Multidrug efflux pumps provide clinically significant levels of drug resistance in a number of Gram-negative hospital-acquired pathogens. These pathogens frequently carry dozens of genes encoding putative multidrug efflux pumps. However, it can be difficult to determine how many of these pumps actually mediate antimicrobial efflux, and it can be even more challenging to identify the ...

P-glycoprotein (P-gp) and cytochrome P450 3A4 (CYP3A4) play a significant role in the disposition and elimination of drugs. The objective of this study was to investigate the mechanism underlying the interaction between sitagliptin (substrate of P-gp and CYP3A4) and verapamil (known modulator of P-gp and CYP3A4) using in vivo, ex vivo and in situ models. Rats were treated with sitagliptin (10 m...