scholarly journals Cytochrome P-450-Dependent Monooxygenase Activities in Prenatal and Postnatal Human Livers: Comparison of Human Liver 7-Alkoxycoumarin O-Dealkylases with Rat Liver Enzymes

1986 ◽  
Vol 40 (3) ◽  
pp. 389-398 ◽  
Author(s):  
Takashi MATSUBARA ◽  
Noriko YAMADA ◽  
Toshio MITOMI ◽  
Seishichi YOKOYAMA ◽  
Yonetaka FUKIISHI ◽  
...  
Keyword(s):  
Rat Liver ◽  
Human Liver ◽  
Liver Enzymes ◽  
Human Livers ◽  
Cytochrome P 450

scholarly journals Stimulation by secretin of bilirubin UDP-glycosyltransferase activities and of cytochrome P-450 concentration in rat liver

1979 ◽  
Vol 182 (3) ◽  
pp. 881-884 ◽  
Author(s):  
G L Ricci ◽  
J Fevery
Keyword(s):  
Rat Liver ◽  
Liver Tissue ◽  
Wistar Rats ◽  
Liver Enzymes ◽  
Glucose Dehydrogenase ◽  
Cytochrome P 450

The activity of bilirubin UDP-glucuronyltransferase in liver tissue was increased 1.5-fold after 90 min of secretion administration (4 i.u./h per kg body wt.) in anaesthetized Wistar rats biopsied half-hourly over a period of 2 h. In unanaesthetized R/A Wistar rats, activities of liver enzymes were assayed after administration secretin for 1 h. Bilirubin UDP-glycosyltransferase activities and cytochrome P-450 concentration were increased, but p-nitrophenol UDP-glucuronyltransferase and UDP-glucose dehydrogenase activities remained unchanged.

scholarly journals Identification of the human liver cytochrome P-450 responsible for coumarin 7-hydroxylase activity

1990 ◽  
Vol 267 (2) ◽  
pp. 365-371 ◽  
Author(s):  
J S Miles ◽  
A W McLaren ◽  
L M Forrester ◽  
M J Glancey ◽  
M A Lang ◽  
...  
Keyword(s):  
Human Liver ◽  
Liver Microsomes ◽  
Microsomal Protein ◽  
Hydroxylase Activity ◽  
Liver Cytochrome ◽  
Partial Length ◽  
Coumarin 7 ◽  
Human Livers ◽  
Cell Expression ◽  
Cytochrome P 450

1. We have constructed a full-length human liver cytochrome P450IIA cDNA from a partial-length clone by oligonucleotide-directed mutagenesis, and subcloned it into the monkey kidney (COS-7) cell expression vector, pSVL. 2. The cDNA encodes a 49 kDa protein with coumarin 7-hydroxylase (COH) activity which cross-reacts with antisera to the mouse cytochrome P-450 isoenzyme responsible for COH activity and comigrates with a human liver microsomal protein. 3. Western blot analysis of a panel of human livers indicates that the level of the 49 kDa protein, detected using antisera to either the mouse COH P-450 or rat P450IIA1 protein, correlates very highly with COH activity. 4. Antisera to the rat P450IIA1 protein can inhibit COH activity in human liver microsomes. Taken together, these data indicate that a member of the P450IIA subfamily is responsible for most, if not all, of the COH activity in human liver.

scholarly journals Identification of human cytochromes P-450 analogous to forms induced by phenobarbital and 3-methylcholanthrene in the rat

1985 ◽  
Vol 232 (3) ◽  
pp. 869-876 ◽  
Author(s):  
D J Adams ◽  
S Seilman ◽  
Z Amelizad ◽  
F Oesch ◽  
C R Wolf
Keyword(s):  
Substrate Specificity ◽  
Rat Liver ◽  
Human Liver ◽  
Western Blots ◽  
Human Samples ◽  
Human Proteins ◽  
Related Proteins ◽  
Cytochrome P 450 ◽  
Antibody Inhibition

Antibodies to four rat liver forms of cytochrome P-450, two phenobarbital-inducible (PB1 and PB2) and two 3-methylcholanthrene-inducible (MC1 and MC2) proteins, have been used to make a structural and functional comparison of rat and human cytochromes P-450. Proteins from both species were identified on Western blots by their reaction with these antibodies. In the human liver preparations, structurally related proteins to PB1 and to PB2 were identified in all the samples tested with apparent Mr values of 51 800 and 54 800 for PB1 and 53 600 and 57 200 for PB2. Considerable variation in the content of the lower-Mr proteins was measured between samples and, as with the rat enzymes, samples which reacted well with anti-PB1 also reacted with anti-PB2, indicating that these proteins are regulated at least to some degree, co-ordinately. The apparent Mr values of the major human proteins identified with anti-MC1 and anti-MC2 were 54 400 and 57 000 respectively. Only six (of 31) human samples contained significant amounts of these proteins. The same six samples which reacted with anti-MC1 also reacted with anti-MC2, again indicating co-ordinate regulation of these two proteins. Antibody inhibition of microsomal 7-ethoxycoumarin and 7-ethoxyresorufin metabolism demonstrated a degree of conservation of substrate specificity related to specific P-450 isoenzymes between the species. However, the contributions of the different P-450 isoenzymes to the human microsomal activity were not always related to the rat enzyme with the highest activity towards these substrates.

scholarly journals Differences in the cytochrome P-450 isoenzymes involved in the 2-hydroxylation of oestradiol and 17 α-ethinyloestradiol. Relative activities of rat and human liver enzymes

1990 ◽  
Vol 267 (1) ◽  
pp. 221-226 ◽  
Author(s):  
S E Ball ◽  
L M Forrester ◽  
C R Wolf ◽  
D J Back
Keyword(s):  
Gene Family ◽  
Human Liver ◽  
Liver Enzymes ◽  
Important Determinant ◽  
Biological Effects ◽  
Gene Families ◽  
Liver Cytochrome ◽  
Human Cytochrome ◽  
Cytochrome P 450 ◽  
Gene Subfamily

The metabolism of oestradiol and 17 alpha-ethinyloestradiol to their 2-hydroxy derivatives is an important determinant in their biological effects. In this work, we have investigated which rat or human cytochrome P-450 isoenzymes are involved in catalysing these reactions. Oestradiol 2-hydroxylation was catalysed by a wide variety of rat cytochrome P-450s from gene families P450IA, P450IIB, P450IIC and P450IIIA. Interestingly, 17 alpha-ethinyloestradiol, which only differs structurally from oestradiol at a position distant from the site of oxidation, was metabolized predominantly by members of the P450IIC gene subfamily. In order to establish which enzymes are responsible for the oxidation of these substrates in man, antibodies to rat liver cytochrome P-450 isoenzymes were used to inhibit these reactions in a panel of human liver microsomal fractions. Also, possible correlations between the proteins recognized by the antibodies and the 2-hydroxylation rate were determined. These experiments provide evidence that 2-hydroxylation of 17 alpha-ethinyloestradiol in man is catalysed by cytochromes from the P450IIC, P450IIE and P450IIIA gene families. In contrast, the major proteins involved in oestradiol metabolism are from the P450IA gene family, although members of the P450IIC and P450IIE gene families may also play a role. These data demonstrate that the differences in the capacity of rat P-450s to metabolize these substrates are also present in the comparable enzymes involved in man, and that a variety of factors will determine the rate of disposition of these compounds in man.

Comparison of Thy–1 expression in human liver cirrhosis and different models of rat liver injury

2006 ◽  
Vol 44 (01) ◽  
Author(s):  
T Mansuroglu ◽  
J Dudas ◽  
B Saile ◽  
D Batusic ◽  
G Ramadori
Keyword(s):  
Liver Cirrhosis ◽  
Liver Injury ◽  
Rat Liver ◽  
Human Liver ◽  
Human Liver Cirrhosis
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