We offer pooled canine hepatic subcellular fractions isolated from Beagle dog liver tissue, demonstrating high enzyme activity level. Options include matching microsomal, S9, and cytosolic fractions from male or female donor pools to minimize variation in canine liver enzyme levels. We also offer dog liver microsomes treated with prototypical inducers for use as a positive control in ex vivo enzyme induction or other drug metabolism studies.
Beagle Dog Liver Subcellular Fractions
Microsomes are supplied in 0.5 mL volume at a concentration of 20 mg/mL in 250 mM sucrose buffer. S9 (1 mL at 20 mg/mL) and cytosol (1 mL at 10 mg/mL) fractions are packaged in a suspension buffer containing 50 mM TRIS-HCI, (pH 7.4 at 4ºC), 150 mM KCI, and 2 mM EDTA.
Utilizing Canine Liver Subcellular Fractions in Preclinical Drug Development
Pooled canine liver fractions are used most often in drug metabolism studies for preclinical research defining a drug candidate’s ADME (absorption, distribution, metabolism, and excretion) profile. Our unique preparation methods allow for large donor pools for higher accuracy in average activity levels; large lots for consistency between assays; and availability of matching S9, microsomes, and cytosol for correlation between studies using different test systems.
Microsomes contain the highest concentration of many important drug-metabolizing enzymes including cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) enzymes. Homogenate and S9 fractions contain a mixture of membranes and soluble enzymes that can be further fractionated into the cytosol and microsomes subcellular fractions. Homogenate and S9 express a wide variety of phase I and phase II enzymes and are recommended for drug metabolism and pharmacokinetics (DMPK) studies. Microsomal fractions are enriched for phase I enzymes, while cytosolic fractions contain various soluble drug-metabolizing enzymes and are a recommended test system for evaluating phase II metabolic reactions of a test compound – especially once reactions have been observed in S9 fractions.
Prototypical Inducer-Treated Microsomes for Ex Vivo Induction Studies
Treating animals with various xenobiotics causes marked induction of liver microsomal CYP enzymes. We offer subcellular fractions from canines, non-human primates and rats treated with prototypical inducers to serve as positive controls for ex vivo enzyme induction studies or for metabolism assays to support data that indicates a specific CYP’s contribution to a compound’s metabolism.
These products are pooled from multiple animals to ensure good representation of the induction and to provide sufficient product availability. The following product information is included with each order of treated animal subcellular fractions:
- Cytochrome P450 content
- Cytochrome b5 content
- NADPH-cytochrome c reductase activity
- Activity of the inducible CYP enzyme
- Dosing regimen
- Animal husbandry conditions
|Product||Description||Volume||Protein Concentration||Induced CYP|
|D1063||Individual Male Beagle Dog Liver Microsomes – Clofibric Acid-Treated – 20mg/mL||0.5mL||20 mg/mL||CYP4A|
|D1073||Individual Male Beagle Dog Liver Microsomes – Saline-Treated – 20mg/mL – Pooled Control||0.5mL||20 mg/mL||Control|
|D1078||Individual Male Beagle Dog Liver Microsomes – 20mg/mL – PB-Treated||0.5mL||20 mg/mL||CYP2B|
|D1083||Individual Male Beagle Dog Liver Microsomes – 20mg/mL – BNF-Treated||0.5mL||20 mg/mL||CYP1A|
|D1095||Individual Male Beagle Dog Liver Microsomes – 20mg/mL – Rifampin-Treated||0.5mL||20 mg/mL||CYP3A|
|D1098||Individual Male Beagle Dog Liver Microsomes – 20mg/mL – Corn Oil-Treated – Pooled Control||0.5mL||20 mg/mL||Control|
Make sure your canine liver microsomes and S9 fractions are properly activated
For best results from assays using microsomes and S9 fractions, we recommend using NADPH regeneration to support high metabolism levels by ensuring that the NADPH levels are not a limiting factor in your incubations. Our preferred system, RapidStartTM, uses an enzymatic reaction that converts NADP to NADPH, which is then used as a cofactor by CYPs and oxidized back to NADP, and the cycle continues ensuring stable NADPH levels throughout the incubation. RapidStartTM NADPH regeneration is easily activated by simply adding water. Our easy-to-use formula is the most convenient and flexible NADPH regenerating system you’ll find, allowing users to easily tailor the system’s capability by simply varying the amount of water added. RapidStartTM is perfect for long- and short-term incubations and supports the function of recombinant enzymes and subcellular fractions, allowing you to achieve the most accurate and reliable data during your in vitro assays.
Don’t see what you need? Other preparations can be made available!
If you require subcellular test systems not available through our standard product offerings, Custom Subcellular Preparations can be easily ordered to meet the specific needs of your study.
Our designated Custom Products team regularly prepares and isolates cells and/or subcellular fractions from more than 45 different species and has capabilities to meet unique needs that are unavailable through most vendors– non-standard rodent strains, farm animals, insects, precarious tissue isolations such as adrenal gland or jejunum. Our specialists can carry out over 40 characterization assays, providing the end user with a good foundation for their DMPK assays. See our Custom Products page for examples of past custom preparations or get in touch with a specialist to find out how we can meet your needs.