METABOLISM OF PREGNENOLONE-3-SULPHATE IN THE PERFUSED DOG LIVER

1965 ◽  
Vol 49 (3) ◽  
pp. 427-435 ◽  
Author(s):  
K. D. Voigt ◽  
J. Tamm ◽  
U. Volkwein ◽  
H. Schedewie
Keyword(s):  
Metabolic Pathways ◽  
Dog Liver ◽  
Steroid Conjugates

ABSTRACT Pregnenolone-sulphate (400 mg) was perfused through isolated dog livers. The following steroids were isolated in the perfusate: pregnenolone, progesterone, dehydroepiandrosterone, androst-5-ene-diol and the two steroid conjugates, i. e. pregnenolone-sulphate and dehydroepiandrosterone-sulphate. Two »free« steroids and one steroid conjugate could not be characterized. A tentative scheme for the metabolic pathways of pregnenolone-sulphate is presented.

THE METABOLISM OF [4-14C]CORTISOL IN PATIENTS WITH COLLAGEN DISEASES

1965 ◽  
Vol 33 (1) ◽  
pp. 33-55 ◽  
Author(s):  
C. H. GRAY ◽  
D. A. SHAW
Keyword(s):  
Rheumatoid Arthritis ◽  
Lupus Erythematosus ◽  
Metabolic Pathways ◽  
Normal Subjects ◽  
Normal Range ◽  
Cortisol Metabolism ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Urinary Steroid ◽  
Steroid Conjugates

SUMMARY The major metabolic pathways of cortisol have been studied in detail after injection of a tracer dose of [4-14C]cortisol in two patients with rheumatoid arthritis and in one with disseminated lupus erythematosus. Results are also presented from preliminary experiments in two other patients with rheumatoid arthritis. The rates of cortisol secretion by the adrenals of all the patients studied were within the normal range and the kinetics of cortisol metabolism were also normal. No abnormalities were found in either the proportions of cortisol, cortisone and 6β-hydroxycortisol in the urinary fraction containing the unconjugated steroids or in that of tetrahydrocortisol, allo-tetrahydrocortisol, tetrahydrocortisone, cortols, cortolones, 11β-hydroxyaetiocholanolone, 11β-hydroxyandrosterone and 11-oxoaetiocholanolone in the fraction released by hydrolysis of the urinary steroid conjugates. The excretion of 6β-hydroxycortisol in a group of patients with rheumatoid arthritis was not significantly greater than that in a similar group of normal subjects in whom the upper limit of the range was higher than values previously reported.

Metabolic pathways for urea production by the amphibian kidney

1965 ◽  
Vol 208 (3) ◽  
pp. 546-554 ◽  
Author(s):  
William A. Brodsky ◽  
Nestor J. Carlisky ◽  
Carlos F. Gonzalez ◽  
Yousif E. Shamoo
Keyword(s):  
Uric Acid ◽  
Metabolic Pathways ◽  
Kidney Tissue ◽  
Kidney Cortex ◽  
Frog Kidney ◽  
Urea Production ◽  
Dog Kidney ◽  
Free Media ◽  
Hydrolysis Of ◽  
Dog Liver

Homogenized kidneys, pooled from bullfrogs ( Rana catesbiana), produce urea in amounts of 1.4–6.4 µmole/g of wet tissue after 1 hr of incubation in substrate-free media. The maximal rate of endogenous urea production under present conditions, 16 µmoles/g kidney per hr, was found during the first 10 min of incubation. In standard tests with added substrates, activity of frog kidney arginase was greater than that of frog liver arginase. However, argininosuccinase, easily detected in frog liver, dog liver, and dog kidney cortex, could not be detected in frog kidney. Additional tests showed that frog kidney homogenates contain uricase, allantoicase, and allantoicase in concentrations similar to those of frog liver tissue. This means that urea forming in frog kidney tissue comes from at least two pathways: one terminating in hydrolysis of arginine, and one terminating in hydrolysis of allantoic acid. In the absence of argininosuccinase, arginine could be derived from degradation of protein or peptides. In view of the oxygen dependency of uric acid-loaded homogenates, allantoic acid is derived from hydrolysis of allantoin which, in turn, derives from the oxidation of uric acid.

Accelerating Metabolic Pathways Simulation using GPUs

2010 ◽  
Author(s):  
Sohan Lal ◽  
Kolin Paul ◽  
James Gomes
Keyword(s):  
Metabolic Pathways

Mapping metabolic pathways in chemical property space paves the way for new leishmanicidals

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
E Vikeved ◽  
R Buonfiglio ◽  
T Kogej ◽  
A Backlund
Keyword(s):  
Chemical Property ◽  
Metabolic Pathways ◽  
Property Space ◽  
The Way

Synthesis and Breakdown of the Universal Precursors to Biological Metabolism Promoted by Ferrous Iron

2018 ◽  
Author(s):  
Kamila B. Muchowska ◽  
Sreejith Jayasree VARMA ◽  
Joseph Moran
Keyword(s):  
Amino Acids ◽  
Chemical Reaction ◽  
Metabolic Pathways ◽  
Ferrous Iron ◽  
Reaction Network ◽  
Tca Cycle ◽  
Chemical Reaction Network ◽  
Metabolic Precursors ◽  
Tca Cycle Intermediates

How core biological metabolism initiated and why it uses the intermediates, reactions and pathways that it does remains unclear. Life builds its molecules from CO<sub>2 </sub>and breaks them down to CO<sub>2 </sub>again through the intermediacy of just five metabolites that act as the hubs of biochemistry. Here, we describe a purely chemical reaction network promoted by Fe<sup>2+ </sup>in which aqueous pyruvate and glyoxylate, two products of abiotic CO<sub>2 </sub>reduction, build up nine of the eleven TCA cycle intermediates, including all five universal metabolic precursors. The intermediates simultaneously break down to CO<sub>2 </sub>in a life-like regime resembling biological anabolism and catabolism. Introduction of hydroxylamine and Fe<sup>0 </sup>produces four biological amino acids. The network significantly overlaps the TCA/rTCA and glyoxylate cycles and may represent a prebiotic precursor to these core metabolic pathways.

Sign in / Sign up

Export Citation Format

Share Document