THE METABOLISM OF URACIL

1957 ◽  
Vol 35 (1) ◽  
pp. 103-111
Author(s):  
Jerrold G. Goldman ◽  
Arnold H. Schein ◽  
Bruce McKay
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Experimental Evidence ◽  
Rat Liver ◽  
Initial Step ◽  
Liver Slices ◽  
Oxidative Pathway ◽  
Mammalian Tissues

Oxygen uptake could not be demonstrated when uracil, uridine, or uridylic acid and various supplements were incubated with rat liver preparations. Attention was directed towards the likelihood that the initial step of uracil catabolism in mammals is a reduction such as occurs in yeasts. Various techniques were employed to measure the possible reduction of uracil to 4,5-dihydrouracil but no experimental evidence was uncovered that this latter compound was formed. While Canellakis has recently shown that the reaction uracil → 4,5-dihydrouracil does take place in mammalian tissues and that TRPH is required, this requirement must be specific since addition of DPNH in the experiments described below was without effect. A small fraction of the ureido carbon (C-2) of uracil-2-C14 was released as carbon dioxide by rat liver slices. None of the results obtained can be reconciled with the oxidative pathway for uracil catabolism in mammals proposed by Cerecedo.

THE METABOLISM OF URACIL

1957 ◽  
Vol 35 (1) ◽  
pp. 103-111
Author(s):  
Jerrold G. Goldman ◽  
Arnold H. Schein ◽  
Bruce McKay
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Experimental Evidence ◽  
Rat Liver ◽  
Initial Step ◽  
Liver Slices ◽  
Oxidative Pathway ◽  
Mammalian Tissues

Oxygen uptake could not be demonstrated when uracil, uridine, or uridylic acid and various supplements were incubated with rat liver preparations. Attention was directed towards the likelihood that the initial step of uracil catabolism in mammals is a reduction such as occurs in yeasts. Various techniques were employed to measure the possible reduction of uracil to 4,5-dihydrouracil but no experimental evidence was uncovered that this latter compound was formed. While Canellakis has recently shown that the reaction uracil → 4,5-dihydrouracil does take place in mammalian tissues and that TRPH is required, this requirement must be specific since addition of DPNH in the experiments described below was without effect. A small fraction of the ureido carbon (C-2) of uracil-2-C14 was released as carbon dioxide by rat liver slices. None of the results obtained can be reconciled with the oxidative pathway for uracil catabolism in mammals proposed by Cerecedo.

scholarly journals Influence of some aliphatic alcohols on the metabolism of rat liver slices

1967 ◽  
Vol 105 (1) ◽  
pp. 93-97 ◽  
Author(s):  
Olof A. Forsander
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Rat Liver ◽  
Marked Effect ◽  
Tricarboxylic Acid Cycle ◽  
Carbon Dioxide Production ◽  
Aliphatic Alcohols ◽  
Liver Alcohol Dehydrogenase ◽  
Liver Slices ◽  
Lactate And Pyruvate

The influence of some aliphatic alcohols on oxygen uptake, carbon dioxide production, acid formation and lactate and pyruvate concentrations of rat liver slices was studied. At the concentrations used, none of the alcohols was found to influence oxygen uptake. Of the alcohols that are not oxidized by liver alcohol dehydrogenase, methanol increased carbon dioxide production, propan-2-ol decreased it and 2-methylpropan-2-ol was without influence. All the alcohols that are oxidized by the enzyme strongly decreased carbon dioxide production. The alcohols that are not oxidized had no marked effect on the lactate/pyruvate concentration ratio, whereas the other alcohols strongly increased the ratio. A highly significant correlation was found between the effects of the alcohol on pyruvate concentration and carbon dioxide production. It is assumed that the shift in the redox potential inhibits the function of the tricarboxylic acid cycle of the liver.

scholarly journals THE EFFECT OF LEAD ACETATE ON OXYGEN UPTAKE OF RAT LIVER SLICES

1941 ◽  
Vol 140 (1) ◽  
pp. 285-291
Author(s):  
Harry D. Baernstein ◽  
J.A. Grand
Keyword(s):  
Oxygen Uptake ◽  
Rat Liver ◽  
Lead Acetate ◽  
Liver Slices

scholarly journals BIOCHEMICAL STUDIES ON SHOCK

1944 ◽  
Vol 79 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Jane A. Russell ◽  
C. N. H. Long ◽  
Alfred E. Wilhelmi
Keyword(s):  
Oxygen Uptake ◽  
Rat Liver ◽  
Liver Tissue ◽  
Kidney Tissue ◽  
Amino Nitrogen ◽  
Water Extract ◽  
Hot Water ◽  
Liver Slices ◽  
Normal Rat ◽  
Severe Shock

1. With increasing severity of shock following hemorrhage in fasted rats there is an increasing depression in the rate of oxygen uptake, in oxygen, of liver slices from the bled animals. The respiration of kidney tissue is only slightly depressed even in severe states of shock. 2. The rates of oxygen uptake of liver tissue from bled rats are nicely correlated with the increases in blood amino nitrogen that follow severe hemorrhage. 3. A supplement of coenzyme factors, in the form of a hot water extract of normal rat liver, increases the oxygen uptake of liver tissue from rats in mild shock, but is without effect on the respiration of liver slices from rats in moderate or severe shock. 4. The ability of rat liver to oxidize succinate is not impaired even in severe shock, but the extra oxygen uptake does not improve the basal rate of respiration of the tissue. 5. Effects on the rate of oxygen uptake of normal rat liver slices comparable to those seen after hemorrhage could be produced by exposing the tissue to an atmosphere of nitrogen for periods of 15 and 60 minutes. This treatment had more marked effects on the respiration of kidney slices than are found after hemorrhage, but the kidney, unlike the liver, exhibited a marked degree of recovery in the presence of glucose. 6. The significance of these findings is briefly discussed.

OXYDATION DES ANABOLIKUMS 1-METHYL-ANDROST-1-EN-17β-OL-3-ON MIT WASSERSTOFFTRANSFER AUF ÖSTRON

1971 ◽  
Vol 67 (3) ◽  
pp. 517-530 ◽  
Author(s):  
Martin Wenzel
Keyword(s):  
Rat Liver ◽  
Anabolic Steroid ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Liver Slices ◽  
Androgen Effects ◽  
Biochemical Difference

ABSTRACT With the aid of metenolon-17α-T a tritium-transfer to oestrone in rat liver slices was demonstrated. This tritium-transfer from metenolon17α-T to oestrone yielding tritium-labelled oestradiol had a higher efficiency in male than in female rat liver. Correspondingly in the presence of metenolon the relation of oestrone to oestradiol is changed more in male than in female rat liver. Looking for biochemical differences between the anabolic steroid metenolon and testosterone the oxydation at C17 was measured in different organs of the rat using 17α-T-labelled steroids. The highest oxydation rate was found for both steroids in the liver. In the sexual organs of male rats the oxydation rate of testosterone was 50–10 times higher than that of the anabolic steroid. This difference was less in sexual organs of female rats. This result of a greater biochemical difference between both steroids in males than in females leads to the question, whether the dissociation between the anabolic and the androgen effects is higher in males than in females.

scholarly journals THE ESTIMATION OF FATTY ACID SYNTHESIS IN RAT LIVER SLICES

1953 ◽  
Vol 205 (1) ◽  
pp. 401-408
Author(s):  
Grace Medes ◽  
Morris A. Spirtes ◽  
Sidney Weinhouse
Keyword(s):  
Fatty Acid ◽  
Rat Liver ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Liver Slices
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