Metabolism of deltamethrin by cow and chicken liver enzyme preparations

1984 ◽  
Vol 32 (2) ◽  
pp. 258-262 ◽  
Author(s):  
M. Humayoun Akhtar
Keyword(s):  
Liver Enzyme ◽  
Chicken Liver ◽  
Enzyme Preparations

Reduction of 7-ketolithocholic acid by human liver enzyme preparations in vitro

1989 ◽  
Vol 256 (1) ◽  
pp. G67-G71
Author(s):  
Y. Amuro ◽  
W. Yamade ◽  
K. Kudo ◽  
T. Yamamoto ◽  
T. Hada ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Liver Enzyme ◽  
Chenodeoxycholic Acid ◽  
Human Liver ◽  
Potassium Phosphate ◽  
Gas Chromatography Mass Spectrometry ◽  
Potassium Phosphate Buffer ◽  
Sodium Potassium ◽  
Enzyme Preparations

The formation of chenodeoxycholic and ursodeoxycholic acids from 7-ketolithocholic acid by human liver preparations was examined in vitro. Liver preparations were incubated with 7-ketolithocholic acid at pH 5.5 in a sodium-potassium-phosphate buffer containing NADPH or NADH. The products formed were analyzed by gas chromatography and gas chromatography-mass spectrometry. Results showed that chenodeoxycholic and ursodeoxycholic acids could be formed from 7-ketolithocholic acid by human liver enzyme(s). The enzyme(s) required NADPH but not NADH as coenzyme and was localized largely in the microsomes. The conjugated 7-ketolithocholic acid, especially the taurine conjugated, was predominantly reduced to chenodeoxycholic acid, whereas the unconjugated 7-ketolithocholic acid was not reduced well to either chenodeoxycholic acid or ursodeoxycholic acid. Thus the reduction of 7-ketolithocholic acid by human liver enzyme(s) was found to be dependent on whether the substrate was conjugated or not.

scholarly journals STUDY ON THE SITE OF BIOSYNTHESIS OF β-GLUCURONIDASE AND ITS APPEARANCE IN LYSOSOME IN NORMAL AND HYPOXIC RATS

1970 ◽  
Vol 18 (8) ◽  
pp. 529-541 ◽  
Author(s):  
JULIEN L. VAN LANCKER ◽  
PATRICK L. LENTZ
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Liver Enzyme ◽  
Rat Liver ◽  
Microsomal Enzymes ◽  
Enzyme Preparations ◽  
Lysosomal Fraction ◽  
Regenerating Rat Liver ◽  
Cell Fractions

For the purpose of investigating the site of synthesis of β-glucuronidase, the enzyme was purified, after injection of labeled amino acids, from various cell fractions of regenerating rat liver. Enzyme preparations purified from microsomal, lysosomal, mitochondrial, nuclear and supernatant fractions had identical catalytic and electrophoretic properties. In nonhypoxic rats, incorporation was detectable only in the microsomal enzymes and maximum labeling occurred 30 min after the injection of the labeled amino acid. No label was detectable in the enzyme purified from the lysosomal fraction of nonhypoxic animals. Labeling of enzyme purified from lysosomal fraction was, however, significant after 2 hr of hypoxia.

Effects of Metal Poisoning on Five Liver Enzymes in the Killifish (Fundulus heteroclitus)

1970 ◽  
Vol 27 (2) ◽  
pp. 383-390 ◽  
Author(s):  
Eugene Jackim ◽  
Janice M. Hamlin ◽  
Stephen Sonis
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Xanthine Oxidase ◽  
Liver Enzyme ◽  
Fundulus Heteroclitus ◽  
Liver Enzymes ◽  
Enzyme Preparations ◽  
Liver Enzyme Activity ◽  
Acid And Alkaline Phosphatase ◽  
Metal Poisoning

Activities of five liver enzymes (acid and alkaline phosphatase, catalase, xanthine oxidase, and ribonuclease) from Fundulus heteroclitus surviving exposure to 96-hr TLm concentrations of salts of six metals (lead, copper, mercury, beryllium, cadmium, and silver) differed markedly from those of unexposed fish. Changes in enzyme activity produced by the exposures were not necessarily the same in magnitude or direction as those observed when the salts were introduced directly into the enzyme preparations. It is proposed that changes in liver enzyme activity may be useful as a kind of biochemical autopsy tool for diagnosing sublethal metal poisoning in fish.

Avian alcohol dehydrogenase: the chicken liver enzyme. Primary structure, cDNA-cloning, and relationships to other alcohol dehydrogenases

1990 ◽  
Vol 194 (2) ◽  
pp. 598-602
Author(s):  
Mats ESTONIUS ◽  
Christina KARLSSON ◽  
Edward A. FOX ◽  
Jan-Olov HOOG ◽  
Barton HOLMQUIST ◽  
...  
Keyword(s):  
Alcohol Dehydrogenase ◽  
Liver Enzyme ◽  
Cdna Cloning ◽  
Primary Structure ◽  
Chicken Liver ◽  
Alcohol Dehydrogenases

scholarly journals Developmental changes of chicken liver AMP deaminase

1985 ◽  
Vol 231 (2) ◽  
pp. 329-333 ◽  
Author(s):  
J Spychała ◽  
K Kaletha ◽  
W Makarewicz
Keyword(s):  
Developmental Stages ◽  
Liver Extract ◽  
Kinetic Studies ◽  
Chicken Liver ◽  
Amp Deaminase ◽  
Enzyme Preparations ◽  
Enzyme Form ◽  
Substrate Saturation ◽  
Two Peaks ◽  
Regulatory Properties

The AMP deaminase activity measured in crude chicken liver extract did not change significantly during development. The livers of 10- and 14-day chick embryos, 1-day, 5-, 10- and 16-week-old chickens and adult hens were examined for the existence of multiple forms of AMP deaminase. Phosphocellulose column chromatography revealed the existence of two peaks of enzyme activity in the liver of 10- and 16-week-old chickens and adult hens. Kinetic studies with the preparations of AMP deaminase revealed sigmoid-shaped substrate-saturation curves at all developmental stages and hyperbolic-shaped saturation curves for the enzyme form appearing in 10-week-old chickens. All AMP deaminases investigated were susceptible to activation by ATP and inhibition by Pi. Kinetic and regulatory properties as well as pH optima of all the enzyme preparations tested indicate that AMP deaminase isolated from the embryos and from 1-day-old chicks was similar to the form I isolated from adult hens and differed significantly from the form II of this enzyme.

scholarly journals Acetylation of serotonin in vitro by a human N-acetyltransferase

1969 ◽  
Vol 113 (4) ◽  
pp. 721-725 ◽  
Author(s):  
Thomas A. White ◽  
John W. Jenne ◽  
David A. Price Evans
Keyword(s):  
Genetic Polymorphism ◽  
Liver Enzyme ◽  
Human Liver ◽  
Natural Substrate ◽  
Enzyme Preparations ◽  
Wide Variability ◽  
Human Livers

1. There is a well-recognized genetic polymorphism for the N-acetylation of isoniazid and sulphamethazine by human livers. 2. Serotonin was found to be acetylated by human liver enzyme preparations and the N-acetylserotonin formed was identified and determined quantitatively. 3. In 13 livers examined there was a wide variability in the capacity to acetylate serotonin that did not correlate with the capacity of the same livers to acetylate isoniazid and sulphamethazine. The results suggest that serotonin is not a natural substrate for the polymorphic N-acetyltransferase and that it may be acetylated by a different enzyme.

scholarly journals The Metabolism of Gammekane and Related Compounds

2021 ◽  
Author(s):  
◽  
Alan Geoffrey Clark
Keyword(s):  
Liver Enzyme ◽  
Gel Filtration ◽  
Dicarboxylic Acids ◽  
In Vitro Metabolism ◽  
Enzyme Preparations ◽  
Sheep Liver ◽  
Lysine Residues ◽  
Complete Exclusion

<p>1. A detailed kinetic study has been made of the glutathione S-aryl-transferases from the New Zealand grass grub (Costelytra zealandica) and from sheep liver. The insect enzyme behaves in accordance with a Michaelis-Menten model for two-substrate enzymes. It is inhibited by the sulphonphthaleins, phthaleins, fluoresceins and dicarboxylic acids competing with glutathione, while the sheep-liver enzyme is not susceptible to this type of inhibition. From this, and other data obtained from a study of the variation of kinetics with pH, it is proposed that two basic groups (possibly lysine residues) are involved in binding of glutathione to the insect enzyme, while only one such group appears in the sheep-liver enzyme. Binding of the aromatic substrate to the enzyme in both species may involve a histidine residue. 2. The accumulation of little significant radioactivity in diluant 2gamma-pentachlorocyclohexene (gamma-PCCH) during the in vitro metabolism of [14C]gamma-hexachlorohexane (gamma-HCH) suggests that the PCCH's are not formed as free intermediates during the metabolism of the HCH's. However, certain ambiguities introduced with the experimental techniques used preclude the complete exclusion of this possibility. 3. gamma-HCH, gamma-PCCH and delta-PCCH metabolized in vivo by M.domestica and C.zealandica and in vitro by preparations from both species, all produce as the principal metabolite a glutathione conjugate with chromatographic properties identical with those of authentic S-(2,4-dichlorophenyl)glutathione. There is, however some doubt as to the identity of the S-substituent moiety. 4. The in vitro metabolism of gamma-HCH and delta-PCCH is glutathione-dependent and is inhibited by various phthaleins and sulphonphthaleins. The in vivo metabolism of delta-PCCH in C.zealandica is profoundly affected by this type of compound, but its effects on the rate of metabolism in vivo of delata-HCH in M.domestica and C.zealandica are only marginal. 5. The enzyme concerned in the metabolism of delta-PCCH has been shown to differ from aryltransferase in M.domestica and C.zealandica by gel filtration techniques and by differences in activity in different enzyme preparations. The delta-PCCH-metabolising activity appears to be associated with a DDT dehydrochlorinase activity. In M.domestica, there appears to be, in addition, a second DDT dehydrochlorinase with only a low cross-specificity towards delta-PCCH.</p>

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