In Vitro Metabolism of 17β-Estradiol by Human Liver Tissue

1975 ◽  
Vol 53 (8) ◽  
pp. 903-906 ◽  
Author(s):  
R. Hobkirk ◽  
Joyce D. Mellor ◽  
Mona Nilsen
Keyword(s):  
Phosphate Buffer ◽  
Human Liver ◽  
Glucuronic Acid ◽  
Liver Homogenate ◽  
Uridine Diphosphate ◽  
Main Metabolite ◽  
Human Liver Tissue ◽  
17Β Estradiol ◽  
Human Liver Slices

17β-[6,7-3H]Estradiol was incubated with adult human liver slices in Krebs–Ringer phosphate buffer containing glucose. Of the identified 3H recovered, 51–76% consisted of estrone-3-sulfate (E13S) and 17β-estradiol-3-sulfate (E23S). E13S was the main metabolite and was found in both tissue and medium. E23S was present only in the medium. Minor amounts of estrogen glucuronides were formed. When a human liver homogenate was incubated with [3H]E2 in a medium fortified with excess uridine diphosphate glucuronic acid only some 4% of conjugation with glucuronic acid was observed. It is suggested that human liver favors sulfurylation as the conjugating mechanism for E2 and E1.

scholarly journals Comparison in different species of biliary bilirubin-IX α conjugates with the activities of hepatic and renal bilirubin-IX α-uridine diphosphate glycosyltransferases

1977 ◽  
Vol 164 (3) ◽  
pp. 737-746 ◽  
Author(s):  
J Fevery ◽  
M Van de Vijver ◽  
R Michiels ◽  
K P M Heirwegh
Keyword(s):  
Glucuronic Acid ◽  
Mammalian Species ◽  
Liver Homogenate ◽  
Species Variation ◽  
Bile Pigment ◽  
Uridine Diphosphate ◽  
Ph Optimum ◽  
Equal Importance ◽  
Liver And Kidney

The bilrubin-IXalpha conjugates in bile and the activities of bilirubin-IX alphax–UDP-glycosyltransferases in liver and kidney were determined for ten species of mammals and for the chicken. 1. In the mammalian species, bilirubin-IX alpha glucuronide was the predominant bile pigment. Excretion of neutral glycosides was unimportant, except in the cat, the mouse, the rabbit and the dog, where glucose and xylose represented 12–41% of total conjugating groups bound to bilirubin-IX alpha. In chicken bile, glucoside and glucuronide conjugates were of equal importance. They probably represent only a small fraction of the total bile pigment. 2. The transferase activities in liver showed pronounced species variation. This was also apparent with regard to activation by digitonin, pH optimum and relative activities of transferases acting on either UDP-glucuronic acid or neutral UDP-sugars. 3. Man, the dog, the cat and the rat excrete bilirubin-IX alpha largely as diconjugated derivatives. In general, diconjugated bilirubin-IX alpha could also be synthesized in vitro with liver homogenate, bilirubin-IX alpha and UDP-sugar. In contrast, for the other species examined, bilirubin pigments consisted predominantly of monoconjugated bilirubin-IX alpha. Synthesis in vitro with UDP-glucuronic acid, UDP-glucose or UDP-xylose as the sugar donor led exclusively to the formation of monoconjugated bilirubin-IX alpha. 4. The transferase activities in the kidney were restricted to the cortex and were important only for the rat and the dog. No activity at all could be detected for several species, including man. 5. Comparison of the transferase activities in liver with reported values of the maximal rate of excretion in bile suggests a close linkage between conjugation and biliary secretion of bilirubin-IX alpha.

Characterization of in vitro healthy and pathological human liver tissue periodicity using backscattered ultrasound signals

2006 ◽  
Vol 32 (5) ◽  
pp. 649-657 ◽  
Author(s):  
Christiano Bittencourt Machado ◽  
Wagner Coelho de Albuquerque Pereira ◽  
Mahmoud Meziri ◽  
Pascal Laugier
Keyword(s):  
Liver Tissue ◽  
Human Liver ◽  
Human Liver Tissue ◽  
Ultrasound Signals

THE METABOLISM OF ALDOSTERONE BY SURVIVING DOG AND HUMAN LIVER SLICES

1960 ◽  
Vol 38 (1) ◽  
pp. 739-756
Author(s):  
Thomas Sandor ◽  
Wojciech J. Nowaczynski ◽  
Jacques Genest
Keyword(s):  
Human Liver ◽  
Chemical Characterization ◽  
Liver Slices ◽  
Metabolic Products ◽  
Reducing Substances ◽  
Dog Liver ◽  
Human Liver Slices ◽  
Acetate Form

Surviving dog liver slices were incubated with d,l-aldosterone-21-monoacetate, d,l-aldosterone, d-aldosterone, and d-aldosterone-21-C14. Human liver slices were incubated with d,l-aldosterone-21-monoacetate and d-aldosterone. The incubations were performed in a Krebs–Ringer–phosphate medium (pH 7.4), with 200 mg glucose added per 100 ml of medium, at a temperature of 37 °C. After incubation, the medium was extracted with chloroform and the crude extract extensively fractionated on column and paper chromatographic systems. In addition to free aldosterone, four metabolic products were isolated, two ring A reduced α-ketolic and two ultraviolet absorbing, non-reducing substances. The partial chemical characterization of these metabolites was attempted. The search for aldosterone metabolites in human urine resulted in the isolation of a substance in acetate form from the urine of a patient suffering from primary aldosteronism which may be identical with one of the ring A reduced metabolites obtained in the in vitro experiments.

scholarly journals Biosynthesis of glycosaminoglycans in bovine cornea. The effect of uridine diphosphate xylose

1970 ◽  
Vol 120 (4) ◽  
pp. 719-723 ◽  
Author(s):  
C. Balduini ◽  
A. Brovelli ◽  
A. A. Castellani
Keyword(s):  
Glucuronic Acid ◽  
Chondroitin Sulphate ◽  
Glucose Dehydrogenase ◽  
Uridine Diphosphate ◽  
Regulatory Effect ◽  
Keratan Sulphate ◽  
Polysaccharide Chain

1. The role of UDP-xylose in the regulation of corneal glycosaminoglycan biosynthesis was investigated. Bovine corneas were incubated with [U-14C]-glucose in the presence and in the absence of the nucleotide, and the radioactivity of chondroitin, chondroitin sulphate and keratan sulphate, as well as of their monosaccharide constituents, was determined. 2. A decrease in the rate of biosynthesis of chondroitin and chondroitin sulphate and an increase in that of keratan sulphate were observed in the samples incubated with UDP-xylose. 3. The UDP-glucuronic acid isolated after the incubation in the presence of UDP-xylose showed a noticeable decrease in the amount of radioactivity incorporated; this result suggests that UDP-xylose inhibits the UDP-glucose dehydrogenase, causing an accumulation of UDP-glucose and consequently an increase in the formation of UDP-galactose and keratan sulphate. 4. Galactose and galactosamine isolated from the polysaccharides showed variations in the amount of radioactivity incorporated in accordance with those observed for the macromolecules; this fact confirms that in the system we used in vitro a real biosynthesis of the polysaccharide chain took place and that the regulatory effect of UDP-xylose was active at the monosaccharide level.

scholarly journals The Selection and Validation of Reference Genes for mRNA and microRNA Expression Studies in Human Liver Slices Using RT-qPCR

Genes ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 763 ◽  
Author(s):  
Tomáš Zárybnický ◽  
Petra Matoušková ◽  
Martin Ambrož ◽  
Zdeněk Šubrt ◽  
Lenka Skálová ◽  
...  
Keyword(s):  
Reference Genes ◽  
Human Liver ◽  
Quantitative Polymerase Chain Reaction ◽  
Three Dimensional ◽  
Transcriptional Response ◽  
Response Analysis ◽  
Tissue Samples ◽  
Human Liver Tissue ◽  
Liver Slices ◽  
Human Liver Slices

The selection of a suitable combination of reference genes (RGs) for data normalization is a crucial step for obtaining reliable and reproducible results from transcriptional response analysis using a reverse transcription-quantitative polymerase chain reaction. This is especially so if a three-dimensional multicellular model prepared from liver tissues originating from biologically diverse human individuals is used. The mRNA and miRNA RGs stability were studied in thirty-five human liver tissue samples and twelve precision-cut human liver slices (PCLS) treated for 24 h with dimethyl sulfoxide (controls) and PCLS treated with β-naphthoflavone (10 µM) or rifampicin (10 µM) as cytochrome P450 (CYP) inducers. Validation of RGs was performed by an expression analysis of CYP3A4 and CYP1A2 on rifampicin and β-naphthoflavone induction, respectively. Regarding mRNA, the best combination of RGs for the controls was YWHAZ and B2M, while YWHAZ and ACTB were selected for the liver samples and treated PCLS. Stability of all candidate miRNA RGs was comparable or better than that of generally used short non-coding RNA U6. The best combination for the control PCLS was miR-16-5p and miR-152-3p, in contrast to the miR-16-5b and miR-23b-3p selected for the treated PCLS. Our results showed that the candidate RGs were rather stable, especially for miRNA in human PCLS.

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