Current Concepts in Drug-Induced Bile Salt Export Pump (BSEP) Interference.
Authors: Kenna JG
Abstract
Numerous drugs have been shown to inhibit the activity of the Bile Salt Export Pump (BSEP in humans, Bsep in animals), and this is now considered to be one of several mechanisms by which idiosyncratic drug-induced liver injury (DILI) may be initiated in susceptible patients. The potential importance of BSEP inhibition by drugs has been recognized by the European Medicines Agency and the International Transporter Consortium, who have recommended that it should be evaluated during drug development when evidence of cholestatic liver injury has been observed in nonclinical safety stu...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
Isolation of endothelial cells from mouse lung.
Authors: Cao G, Abraham V, DeLisser HM
Abstract
The isolation of endothelial cells (ECs) from knockout and transgenic mouse lines provides the opportunity to study the endothelial-specific activities of a targeted molecule. As a means of pursuing these types of investigations, the protocols described in this unit provide a reliable method for isolating lung microvascular ECs from mouse neonatal pups that can be serially passaged. These protocols are useful in settings where mouse age is irrelevant and a pure population of pulmonary vascular ECs, uncontaminated by other cells, is needed. When a specific sou...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
F3 -Isoprostanes as a Measure of in vivo Oxidative Damage in Caenorhabditis elegans.
Authors: Nguyen TT, Aschner M
Abstract
Oxidative stress has been implicated in the development of a wide variety of disease processes, including cardiovascular disease, cancer, and neurodegenerative diseases, as well as progressive and normal aging processes. Isoprostanes (IsoPs) are prostaglandin-like compounds that are generated in vivo from lipid peroxidation of arachidonic acid (AA, C20:4, ω-6) and other polyunsaturated fatty acids (PUFA). Since the discovery of IsoPs by Morrow and Roberts in 1990, quantification of IsoPs has been shown to be an excellent source of biomarkers of in vivo oxidative dama...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
The history and use of human hepatocytes for the treatment of liver diseases: the first 100 patients.
In conclusion, hepatocyte transplants have proven effective particularly in cases of metabolic liver disease where reversal or amelioration of the characteristic symptoms of the disease is easily quantified. However, no patients have been completely corrected of a metabolic liver disease for a significant amount of time by hepatocyte transplantation alone. It is likely that future developments in new sources of cells for transplantation will be required before this cellular therapy can be fully implemented and available for large numbers of patients. © 2014 by John Wiley & Sons, Inc.
PMID: 25378242 [PubMed - ...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
Methods to measure olfactory behavior in mice.
Authors: Zou J, Wang W, Pan YW, Lu S, Xia Z
Abstract
Mice rely on the sense of olfaction to detect food sources, recognize social and mating partners, and avoid predators. Many behaviors of mice, including learning and memory, social interaction, fear, and anxiety are closely associated with their function of olfaction, and behavior tasks designed to evaluate those brain functions may use odors as cues. Accurate assessment of olfaction is not only essential for the study of olfactory system but also critical for proper interpretation of various mouse behaviors, especially learning and memory, emotionality ...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
How to measure alterations in alveolar barrier function as a marker of lung injury.
We describe a simple method to assess the AFC rate in normal and pathological conditions in mice. We also describe two complementary methods to assess the alveolar-capillary barrier function, which require measuring the concentration of endogenous plasma proteins in bronchoalveolar lavage fluid and detection of tight-junction proteins in lung tissue by immunofluorescence. © 2015 by John Wiley & Sons, Inc.
PMID: 25645245 [PubMed - in process] (Source: Current Protocols in Toxicology)
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
Inhalation toxicology methods: the generation and characterization of exposure atmospheres and inhalational exposures.
Authors: Chen LC, Lippmann M
Abstract
In this unit, the need for laboratory-based inhalation toxicology studies, the historical background on adverse health effects of airborne toxicants, and the benefits of advance planning for the building of analytic options into the study design to maximize the scientific gains to be derived from the investments in the study are outlined. The following methods are described: (1) the generation and characterization of exposure atmospheres for inhalation exposures in humans and laboratory animals; (2) the delivery and distribution into and within whole-body exposure cham...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
Metabolism of xenobiotics by aldehyde oxidase.
Authors: Dalvie D, Zientek M
Abstract
Aldehyde oxidase (AO) is a cytosolic molybdoflavoprotein whose contribution to the metabolism and clearance of xenobiotics-containing heterocyclic rings has attracted increased interest in recent years. This unit details methods for identification and confirmation of AO as a metabolic pathway as well as a method for estimating clearance of compounds that are AO substrates. © 2015 by John Wiley & Sons, Inc.
PMID: 25645247 [PubMed - in process] (Source: Current Protocols in Toxicology)
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
RNASeq in C. elegans Following Manganese Exposure.
Authors: Parmalee NL, Maqbool SB, Ye B, Calder B, Bowman AB, Aschner M
Abstract
Manganese is a metal that is required for optimal biological functioning of organisms. Absorption, cellular import and export, and excretion of manganese are all tightly regulated. While some genes involved in regulation, such as DMT-1 and ferroportin, are known, it is presumed that many more are involved and as yet unknown. Excessive exposure to manganese, usually in industrial settings such as mining or welding, can lead to neurotoxicity and a condition known as manganism that closely resembles Parkinson's disease. Elucidatin...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
Pre-Plated Cell Lines for ADMETox Applications in the Pharmaceutical Industry.
Authors: Torres FM, Sáfár Z, Domínguez J, Kurunczi A, Kis E, Magnan R, Jani M, Nicolás JO, Krajcsi P
Abstract
Membrane transporters significantly modulate membrane permeability of endobiotics and xenobiotics, such as bile acids and drugs, respectively. Various in vitro methods have been established for both ATP-binding cassette (ABC) transporters to examine cellular efflux and uptake, and for solute carriers (SLC) to examine cellular uptake of substrates. Cell-based systems are the models of choice to test drug-transporter interactions as well as drug-drug interactions for research and regulatory purpo...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
Measuring Mitochondrial Membrane Potential with a Tetraphenylphosphonium-Selective Electrode.
Authors: Moreno AJ, Santos DL, Magalhães-Novais S, Oliveira PJ
Abstract
Mitochondrial bioenergetics is based on the generation of the protonmotive force by the electron transport chain. The protonmotive force is used by mitochondria for different critical aspects of its normal function, ranging from calcium accumulation to the synthesis of ATP. The transmembrane electric potential (ΔΨ) is the major component of the protonmotive force and is also the main responsible for ATP synthesis by mitochondrial ATP synthase. Although several methods can be used to measure the ΔΨ, the use of the tetraphenylphosph...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
Alkaline Comet Assay for Assessing DNA Damage in Individual Cells.
Authors: Pu X, Wang Z, Klaunig JE
Abstract
Single-cell gel electrophoresis, commonly called a comet assay, is a simple and sensitive method for assessing DNA damage at the single-cell level. It is an important technique in genetic toxicological studies. The comet assay performed under alkaline conditions (pH >13) is considered the optimal version for identifying agents with genotoxic activity. The alkaline comet assay is capable of detecting DNA double-strand breaks, single-strand breaks, alkali-labile sites, DNA-DNA/DNA-protein cross-linking, and incomplete excision repair sites. The inclusion of diges...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
Determination of Metabolic Stability Using Cryopreserved Hepatocytes from Rainbow Trout (Oncorhynchus mykiss).
Authors: Fay KA, Nabb DL, Mingoia RT, Bischof I, Nichols JW, Segner H, Johanning K, Han X
Abstract
Trout provide a relatively easy source of hepatocytes that can be cryopreserved and used for a range of applications including toxicity testing and determination of intrinsic clearance. Standard protocols for isolating, cryopreserving, and thawing rainbow trout hepatocytes are described, along with procedures for using fresh or cryopreserved hepatocytes to assess metabolic stability of xenobiotics in fish by means of a substrate depletion approach. Variations on these methods, troubleshooting tips, and direct...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
High-resolution multi-photon imaging of morphological structures of caenorhabditis elegans.
Authors: Bixel MG, Fretham SJ, Aschner M
Abstract
In this protocol, we combine two-photon excitation fluorescence to visualize in caenorhabditis elegans (C. elegans) dopaminergic (DAergic) neurons and their processes with non-linear optical measurements to reconstruct the three-dimensional architecture of the pharyngeal region and the muscular system of the anterior and mid-body region. Femto second laser pulses excite second-harmonic generation (SHG) and third harmonic generation (THG) signals, which show detailed structural information regarding the organization of myofibrils that are arranged around the...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
Quantification of Glutathione in Caenorhabditis elegans.
Authors: Caito SW, Aschner M
Abstract
Glutathione (GSH) is the most abundant intracellular thiol with diverse functions from redox signaling, xenobiotic detoxification, and apoptosis. The quantification of GSH is an important measure for redox capacity and oxidative stress. This protocol quantifies total GSH from Caenorhabditis elegans, an emerging model organism for toxicology studies. GSH is measured using the 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) cycling method originally created for cell and tissue samples but optimized for whole worm extracts. DTNB reacts with GSH to from a 5'-thio-2-nitrobenzoi...
Source: Current Protocols in Toxicology - December 21, 2015 Category: Toxicology Tags: Curr Protoc Toxicol Source Type: research
