HPLC-fluorescence Determination of EROD Activity in Wistar Rat Liver Microsomes Obtained by Two Different Extraction Procedures

2013 ◽  
Vol 9 (1) ◽  
pp. 43-53
Author(s):  
Katia Roberta A. Belaz ◽  
Regina V. Oliveira
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
Wistar Rat ◽  
Erod Activity ◽  
Rat Liver Microsomes ◽  
Extraction Procedures ◽  
Fluorescence Determination

Determination of metabolic profile of anti-malarial trioxane CDRI 99/411 in rat liver microsomes using HPLC

2011 ◽  
Vol 26 (1) ◽  
pp. 115-122 ◽  
Author(s):  
Smriti Mishra ◽  
Lakshmi Manickavasagam ◽  
Girish Kumar Jain
Keyword(s):  
Rat Liver ◽  
Metabolic Profile ◽  
Liver Microsomes ◽  
Rat Liver Microsomes

scholarly journals Reconstitution of purified Wistar rat liver bilirubin UDP-glucuronyltransferase into Gunn-rat liver microsomes

1982 ◽  
Vol 201 (3) ◽  
pp. 653-656 ◽  
Author(s):  
B Burchell
Keyword(s):  
Enzyme Activity ◽  
Rat Liver ◽  
Specific Activity ◽  
Liver Microsomes ◽  
Wistar Rat ◽  
Transferase Activity ◽  
Rat Liver Microsomes ◽  
Phosphatidylcholine Liposomes ◽  
Gunn Rat ◽  
Rigid Environment

1. Reconstitution of purified bilirubin UDP-glucuronyltransferase from Wistar-rat liver into Gunn-rat liver microsomes provides a better environment than phosphatidylcholine liposomes, such that the final specific activity of the Wistar-rat liver enzyme was increased up to 85 units/mg of protein. 2. Gunn- and Wistar-rat liver microsomes were equally effective for reconstitution of the purified enzyme. 3. The transferase activity does not appear to be fully expressed in the more rigid environment of foetal Wistar-rat liver microsomes. 4. These reconstitution experiments reveal a final specific activity for the purified bilirubin UDP-glucuronyltransferase consistent with the capacity of the whole rat liver to glucuronidate bilirubin and indicate that the absence of this enzyme activity in Gunn-rat liver microsomes is not due to an abnormal microenvironment.

A Direct, Highly Sensitive Fluorometric Assay for a Microsomal Cytochrome P450-Mediated O-Demethylation Using a Novel Coumarin Analog as Substrate

2000 ◽  
Vol 55 (11-12) ◽  
pp. 915-922 ◽  
Author(s):  
René Roser ◽  
Helmut Thomas
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
Fluorometric Assay ◽  
Excitation Wavelength ◽  
Monooxygenase System ◽  
Rat Liver Microsomes ◽  
Monooxygenase Activity ◽  
Continuous Increase ◽  
Highly Sensitive

A highly sensitive fluorometric assay for the determination of monooxygenase activity in liver microsomes is described. The assay is based on the use of 3-chloro-7-methoxy-4-methylcoumarin which is demethylated to 3-chloro-7-hydroxy-4-methylcoumarin. The rate of formation of 3-chloro-7-hydroxy-4-methylcoumarin was recorded as an increase of fluorescence (λA = 380 nm, λF = 480 nm ) with time. When 3-chloro-7-methoxy-4-methylcoumarin was incubated in the presence of MgCl2and NADPH with rat liver microsomes, a continuous increase of the fluorescence could be measured. The reaction proceeded linearly for about 10 min and at least up to a concentration of 0.1 mg/ml of microsomal protein. Besides 3-chloro-7-hydroxy-4-methylcoumarin a hydroxylated derivative of the substrate was formed as a second metabolite during the incubation. Using an excitation wavelength of 480 nm and a fluorescence/em ission w avelength of 480 nm, the fluorescence of this substance (λA = 338 nm, λF = 422 nm ) amounted only to about 1% of the fluorescence of the main product. The use of 3-chloro-7-methoxy-4-methylcoumarin as substrate enables the fluorometric determination of the O-dealkylation activity of a cytochrom e P450-dependent monooxygenase system in rat liver which is inducible by phenobarbital but not by 3-methylcholanthrene.

Simple method for determination of the active metabolite of the inotropic drug pimobendan in rat liver microsomes

2000 ◽  
Vol 744 (1) ◽  
pp. 189-193 ◽  
Author(s):  
Shin-ichiro Kuriya ◽  
Shigeru Ohmori ◽  
Mayuko Hino ◽  
Chiaki Senda ◽  
Kenji Sakai ◽  
...  
Keyword(s):  
Rat Liver ◽  
Active Metabolite ◽  
Liver Microsomes ◽  
Rat Liver Microsomes ◽  
Simple Method ◽  
Inotropic Drug

scholarly journals Bilirubin mono- and di-glucuronide formation by purified rat liver microsomal bilirubin UDP-glucuronyltransferase

1984 ◽  
Vol 223 (2) ◽  
pp. 461-465 ◽  
Author(s):  
B Burchell ◽  
N Blanckaert
Keyword(s):  
Rat Liver ◽  
Microsomal Fraction ◽  
Total Bilirubin ◽  
Glucuronic Acid ◽  
Liver Microsomes ◽  
Wistar Rat ◽  
Zero Order ◽  
Rat Liver Microsomes ◽  
Order Kinetic ◽  
Hepatic Microsomes

Highly purified bilirubin UDP-glucuronyltransferase from Wistar-rat liver, when reconstituted with Gunn-rat liver microsomes (microsomal fraction), was able to catalyse the conversion of unesterified bilirubin into both bilirubin monoglucuronide and diglucuronide. Under zero-order kinetic conditions for monoglucuronide formation, the fraction of bilirubin diglucuronide formed by incubation of bilirubin with the reconstituted highly purified transferase accounted for 18% of total bilirubin glucuronides, which was only slightly lower than the fraction of diglucuronides (23% of total bilirubin glucuronides) formed by incubation with hepatic microsomes in the presence of UDP-N-acetylglucosamine or Lubrol. The reconstituted purified enzyme also catalysed the UDP-glucuronic acid-dependent conversion of bilirubin monoglucuronide into diglucuronide and, when bilirubin was incubated with UDP-glucose or UDP-xylose, the formation of bilirubin glucosides and xylosides respectively. These results suggest that a single microsomal bilirubin UDP-glycosyltransferase may be responsible for the formation of bilirubin mono- and di-glycosides.

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