Formation of glutathione conjugates as metabolites of 7,12-dimethylbenz-[a] anthracene by rat-liver homogenates

1973 ◽  
Vol 22 (14) ◽  
pp. 1781-1791 ◽  
Author(s):  
Joan Booth ◽  
Gerald R. Keysell ◽  
Peter Sims
Keyword(s):  
Rat Liver ◽  
Glutathione Conjugates ◽  
Liver Homogenates

scholarly journals Epoxy derivatives of aromatic polycyclic hydrocarbons. The preparation of benz[a]anthracene 8,9-oxide and 10,11-dihydrobenz[a]anthracene 8,9-oxide and their metabolism by rat liver preparations

1971 ◽  
Vol 125 (1) ◽  
pp. 159-168 ◽  
Author(s):  
P. Sims
Keyword(s):  
Rat Liver ◽  
Reduced Glutathione ◽  
Mercapturic Acids ◽  
Polycyclic Hydrocarbons ◽  
Glutathione Conjugates ◽  
Liver Homogenates ◽  
Derivatives Of ◽  
Related Compounds

The syntheses of 10,11-dihydrobenz[a]anthracene 8,9-oxide, benz[a]anthracene 8,9-oxide and 9-hydroxybenz[a]anthracene are described, together with those of a number of related compounds. The epoxides react both chemically and enzymically with water to yield the corresponding dihydrodiols and with reduced glutathione to form glutathione conjugates, and they react chemically with N-acetylcysteine to yield the corresponding mercapturic acids. 8,9-Dihydro-8,9-dihydroxybenz[a]anthracene, formed enzymically from benz[a]anthracene 8,9-oxide, was identical with a dihydrodiol formed when benz[a]anthracene was metabolized by rat liver homogenates. Similarly 10,11-dihydrobenz[a]anthracene 8,9-oxide yielded a dihydrodiol identical with the product formed when 10,11-dihydrobenz[a]anthracene was metabolized.

scholarly journals Epoxy derivatives of aromatic polycyclic hydrocarbons. The preparation and metabolism of epoxides related to benzo[a]pyrene and to 7,8- and 9,10-dihydrobenzo[a]pyrene

1972 ◽  
Vol 128 (2) ◽  
pp. 265-277 ◽  
Author(s):  
J. F. Waterfall ◽  
P. Sims
Keyword(s):  
Rat Liver ◽  
Biochemical Properties ◽  
Trans Isomers ◽  
Polycyclic Hydrocarbons ◽  
Glutathione Conjugates ◽  
Liver Homogenates ◽  
Cis And Trans ◽  
Derivatives Of

Products that appeared to be mainly benzo[a]pyrene 7,8-oxide and benzo[a]pyrene 9,10-oxide were synthesized and their chemical and biochemical properties were investigated. The oxides were unstable and readily rearranged to phenols. They were converted by rat liver homogenates and microsomal preparations into phenols and dihydrodiols, but glutathione conjugates were not formed in appreciable amounts. The dihydrodiols formed from benzo[a]pyrene 7,8- and 9,10-oxide by rat liver microsomal preparations were identical in their chromatographic and spectrographic properties with dihydrodiols formed when benzo[a]pyrene was metabolized by rat liver homogenates. 9,10-Dihydrobenzo[a]pyrene 7,8-oxide and 7,8-dihydrobenzo[a]pyrene 9,10-oxide were also synthesized. They were converted by rat liver homogenates and microsomal preparations into the related cis- and trans-dihydroxy compounds. Glutathione conjugates were formed from the oxides by rat liver homogenates. Both 7,8- and 9,10-dihydrobenzo[a]pyrene were metabolized by rat liver homogenates to mainly the trans-isomers of the related dihydroxy compounds. In experiments with boiled homogenates, the benzo[a]pyrene oxides were converted into phenols, whereas the dihydrobenzo[a]pyrene oxides yielded small amounts of the related dihydroxy compounds.

scholarly journals The metabolism of 7- and 12-methylbenz[a]-anthracene and their derivatives

1967 ◽  
Vol 105 (2) ◽  
pp. 591-598 ◽  
Author(s):  
P Sims
Keyword(s):  
Rat Liver ◽  
Glutathione Conjugates ◽  
Liver Homogenates ◽  
Derivatives Of ◽  
Lead Tetra Acetate

1. 7- and 12-Methylbenz[a]anthracene were converted by rat-liver homogenates into the corresponding hydroxymethyl derivatives, products that are probably the 8,9-dihydro-8,9-dihydroxy and the 5,6-dihydro-5,6-dihydroxy derivatives, and a number of phenolic products. 2. Both hydrocarbons were converted into glutathione conjugates; that from 7-methylbenz[a]anthracene was also formed, together with 5,6-dihydro-5,6-dihydroxy- and 5-hydroxy-benz[a]anthracene, from 5,6-epoxy-5,6-dihydro-7-methylbenz[a]anthracene. 3. 7- and 12-Hydroxymethyl-benz[a]anthracene were converted into products that are probably 8,9-dihydro-8,9-dihydroxy derivatives, and into phenols. 4. The preparation of a number of derivatives of the hydrocarbons is described. 5. The oxidation of the hydrocarbons with lead tetra-acetate was investigated.

scholarly journals THE INCORPORATION OF THE CARBOXYL CARBON FROM ACETATE INTO CHOLESTEROL BY RAT LIVER HOMOGENATES

1954 ◽  
Vol 206 (1) ◽  
pp. 471-481 ◽  
Author(s):  
Ivan D. Frantz ◽  
Nancy L.R. Bucher ◽  
Henny S. Schneider ◽  
Naomi H. McGovern ◽  
Ruth Kingston
Keyword(s):  
Rat Liver ◽  
Liver Homogenates ◽  
Carboxyl Carbon

scholarly journals STIMULATION BY DINITROPHENOL OF FORMATION OF MELANIN-LIKE SUBSTANCE FROM TYROSINE BY RAT LIVER HOMOGENATES

1957 ◽  
Vol 225 (2) ◽  
pp. 735-744
Author(s):  
Henry Kamin ◽  
Mildred A. Koon ◽  
Philip Handler
Keyword(s):  
Rat Liver ◽  
Liver Homogenates

Glucocorticoid effects on respiration and metabolism by rat liver homogenates

1962 ◽  
Vol 202 (2) ◽  
pp. 343-346 ◽  
Author(s):  
Dennis D. Goetsch ◽  
L. E. McDonald
Keyword(s):  
Lactic Acid ◽  
Oxygen Uptake ◽  
Rat Liver ◽  
Inorganic Phosphate ◽  
Chronic Administration ◽  
Glucocorticoid Treatment ◽  
Carbohydrate Utilization ◽  
Protein Levels ◽  
Liver Homogenates ◽  
And Control

The effects of glucocorticoid administration on oxygen uptake, glucose and glycogen disappearance, lactic acid formation, and inorganic phosphate and protein levels in rat liver homogenates have been studied. A single injection of hydrocortisone, prednisolone, or 9 α-fluoroprednisolone 5 hr before sacrifice resulted in a highly significant increase in oxygen uptake by rat liver homogenates, whereas chronic administration of prednisolone daily for 7 days caused a marked inhibition in homogenate respiration. Glycolytic rate did not appear to be affected by single injections since endogenous carbohydrate utilization was similar in liver homogenates prepared from control and treated animals. Incubation of liver homogenates under aerobic conditions disclosed that inorganic phosphate levels were decreased in homogenates from corticoid-treated rats, whereas these levels were similar in treated and control liver homogenates incubated under nitrogen. Under anaerobic conditions, liver homogenates from treated rats accumulated lactic acid more rapidly than untreated liver homogenates. Glucocorticoid treatment did not appear to affect protein disappearance since no differences between protein levels in treated and untreated rat liver homogenates were detected following incubation.

Substrate specificity of iodothyronine 5′-deiodinase in rat liver homogenates and its requirements of divalent cations in vitro

Life Sciences ◽  
1986 ◽  
Vol 38 (24) ◽  
pp. 2231-2238 ◽  
Author(s):  
Shinya Kobayshi ◽  
Yan Gao ◽  
Richard L. Ong ◽  
Constance S. Pittman
Keyword(s):  
Substrate Specificity ◽  
Rat Liver ◽  
Divalent Cations ◽  
Liver Homogenates
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