scholarly journals Hepatic collagenolytic activity in rats after carbon tetrachloride poisoning

1969 ◽  
Vol 115 (4) ◽  
pp. 843-847 ◽  
Author(s):  
Chisato Hirayama ◽  
Kaichiro Hiroshige ◽  
Tomiichi Masuya
Keyword(s):  
Single Dose ◽  
Carbon Tetrachloride ◽  
Free Amino ◽  
Supernatant Fraction ◽  
Acid Proteinase ◽  
Collagenolytic Activity ◽  
Hydroxyproline Content ◽  
Experimental Conditions ◽  
Carbon Tetrachloride Poisoning ◽  
Acid Soluble Collagen

1. Collagenolytic activity towards acid-soluble collagen labelled with [14C]-proline was assayed in rat liver with and without carbon tetrachloride poisoning. The products of enzymic digestion were found to be free amino acids and peptides. 2. The hepatic collagenolytic activity increased under conditions of single-dose and subacute carbon tetrachloride poisoning, and correlated with hydroxyproline content. The highest activity was found during recovery from subacute poisoning. 3. Under the same experimental conditions, hepatic acid-proteinase activity changed independently of the collagenolytic activity and also of hepatic hydroxyproline content. 4. The increased collagenolytic activity during carbon tetrachloride poisoning was found mainly in the supernatant fraction. 5. The ratio of the collagenolytic activity to hepatic hydroxyproline content increased during recovery from single-dose and subacute poisoning, and decreased during subacute poisoning.

scholarly journals Quantitative and metabolic changes of hepatic collagens in rats after carbon tetrachloride poisoning

1970 ◽  
Vol 118 (2) ◽  
pp. 229-232 ◽  
Author(s):  
Chisato Hirayama ◽  
Ikuo Morotomi ◽  
Kaichiro Hiroshige
Keyword(s):  
Carbon Tetrachloride ◽  
Rat Liver ◽  
Collagenolytic Activity ◽  
Normal Range ◽  
Carbon Tetrachloride Poisoning ◽  
Soluble Collagen ◽  
Insoluble Collagen ◽  
Acid Soluble Collagen ◽  
Soluble Acid

1. The collagen hydroxyproline in rat liver was composed of 3.5% neutral-soluble collagen, 4.9% acid-soluble collagen and 91.6% insoluble collagen. In labelling studies with [14C]proline in vitro, the specific radioactivities of neutral-soluble, acid-soluble and insoluble collagens in rat liver were found to be 233000, 69000 and 830d.p.m./μmol of hydroxyproline respectively after 1h. 2. During subacute carbon tetrachloride poisoning the hepatic content of insoluble collagen markedly increased, whereas those of soluble collagens did not change. During recovery from subacute poisoning hepatic contents of soluble collagens were markedly decreased. 3. After 8 weeks of carbon tetrachloride poisoning the specific radioactivities of hepatic soluble collagens increased, while that of insoluble collagen decreased. During recovery from subacute poisoning, the specific radioactivities of soluble collagens decreased to the normal range and that of insoluble collagen further decreased. 4. Hepatic collagenolytic activity solubilizing insoluble collagen, which differs from mammalian collagenase, decreased under the conditions of the subacute poisoning and also during recovery from subacute poisoning.

scholarly journals The effect of diet on carbon tetrachloride metabolism

1967 ◽  
Vol 105 (3) ◽  
pp. 1055-1060 ◽  
Author(s):  
A. A. Seawright ◽  
A. E. M. McLean
Keyword(s):  
Carbon Dioxide ◽  
Single Dose ◽  
Carbon Tetrachloride ◽  
Oral Dose ◽  
Protein Content ◽  
Microsomal Protein ◽  
Carbon Tetrachloride Poisoning ◽  
Liver Slices ◽  
Highly Sensitive

1. Blood and liver concentrations of carbon tetrachloride were measured, at intervals after an oral dose, in rats given stock and protein-free diets. The values did not correlate with the resistance to poisoning found in the rats on protein-free diets. 2. The metabolism of carbon tetrachloride to carbon dioxide in vivo and in liver microsomal preparations was depressed in animals given protein-free diets. 3. Rats given a single dose of DDT [1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane] were highly sensitive to carbon tetrachloride poisoning. The livers of such animals had an increased microsomal protein content and greatly increased microsomal activity in the demethylation of Pyramidon (aminopyrine) and in the conversion of 14CCl4 into 14CO2. 4. The incorporation of [14C]leucine into protein by liver slices was depressed by carbon tetrachloride. This effect was decreased by addition of SKF525A (2-diethylaminoethyl 2,2-diphenyl-2-propylacetate) and in slices from rats given protein-free diets. It is suggested that the toxicity of carbon tetrachloride is closely linked to its metabolism.

Reductive Activation of Carbon Tetrachloride by Human Haemoglobin

1993 ◽  
Vol 21 (1) ◽  
pp. 57-64
Author(s):  
Roberta Ferrara ◽  
Michela Rezzadore ◽  
Stefano Cazzaro ◽  
Roberto Tolando ◽  
Maurizio Manno
Keyword(s):  
Carbon Monoxide ◽  
Carbon Tetrachloride ◽  
Anaerobic Incubation ◽  
Reductive Activation ◽  
Anaerobic Conditions ◽  
Prosthetic Group ◽  
Experimental Conditions ◽  
Human Haemoglobin ◽  
Reductive Metabolism

The reductive metabolism of carbon tetrachloride (CC14) by human haemoglobin (Hb) was observed in vitro by absolute absorption spectra recorded under anaerobic conditions. The following results were obtained: 1) a decrease of the 430nm peak typical of free reduced Hb (Hb2+); 2) the formation of a shoulder of absorbance, attributable to the production of a complex between Hb2+ and a metabolite of CC14 carbon monoxide (Hb-CO); and 3) the oxidation of some Hb2+ to methaemoglobin (Hb3+). The concentration of these three forms — Hb2+, Hb-CO and Hb3+ — during anaerobic incubation of Hb with CC14 was calculated algebraically from the absolute spectra. CO production was then calculated from the concentration of Hb-CO, using a suitable calibration curve. Interestingly, under identical experimental conditions, a substrate-dependent loss of Hb-derived haem, but not of Hb itself nor of haem-derived porphyrin fluorescence, was measured. Preliminary HPLC studies to clarify the discrepancy and, in particular, the role and fate of the haem group, showed two substrate-dependent modified haem products. The results indicate that human Hb is able to catalyse the reductive activation of CCl4, and suggest that, during the process, its prosthetic group haem may be modified by CC14 metabolites to products which maintain a tetrapyrrolic structure but are unable to react with pyridine.

scholarly journals A Betalain-rich Dietary Supplement, But Not PETN, Increases Vasodilation and Nitric Oxide: A Comparative, Single-dose, Randomized, Placebo-controlled, Blinded, Crossover Pilot Study

2020 ◽  
Vol 10 (1) ◽  
pp. 26
Author(s):  
B. V. Nemzer ◽  
Z. Pietrzkowski ◽  
J. M. Hunter ◽  
J. L. Robinson ◽  
B. Fink
Keyword(s):  
Nitric Oxide ◽  
Single Dose ◽  
Endothelial Function ◽  
Dietary Supplement ◽  
Athletic Performance ◽  
Side Reaction ◽  
Nitrate Content ◽  
Organic Nitrate ◽  
Experimental Conditions ◽  
Study Results

Nutraceutical supplements have demonstrated promise as agents for improving athletic performance and for positively affecting cardiovascular health and vigor through modulation of endothelial function at the cellular level. High-nitrate products, such as red beet juices and powders, have been observed to improve athletic performance potentially through increased nitric oxide (NO) concentrations in the blood. Similarly, a patented low nitrate, low sugar betalain-rich supplement has also been reported to significantly improve athletic performance. To the best of our knowledge, no acute clinical studies have been conducted that have demonstrated the comparative efficacies of high-nitrate or betalain-rich, low nitrate materials on measures of endothelial function in real time. In this acute single-dose, double-blinded, randomized, placebo-controlled, crossover study, we examined the effects of the betalain-rich low nitrate dietary supplement, (BRS, 50mg), in comparison to pentaerythritol tetranitrate (PETN, 40mg), a pharmaceutical drug that is a potent source of organic nitrate, and a placebo, on various measures of endothelial function for up to 4-hours post-ingestion. More specifically, in order to gauge post-treatment changes in endothelial function we measured flow-mediated dilation (FMD), nitrite (NO2)/nitrate (NO3) content, circulating nitrosyl-hemoglobin (NOHb) concentration, and cellular metabolic activity (CMA) measured as generation of reactive oxygen species, a side reaction of oxidative-reductive cellular metabolism. Ten participants completed all arms of the study. Results suggest that within 2 hours, BRS, but not PETN or placebo, resulted in significantly elevated levels of NOHb (a measure of bioavailable NO●) (p = 0.017) and increased vasodilation as measured by FMD, (p = 0.025). As expected, due to its high nitrate content, NO2/NO3 levels were increased by PETN within 2-hours (p = 0.048), but not by BRS or placebo. Finally, under these experimental conditions, PETN and BRS produced no significant changes for mitochondrial, NADPH-oxidase dependent or cellular CMA. These data provide preliminary support for single-dose effectiveness of BRS, but not PETN, on levels of bioavailable NO● and FMD, both important measures of endothelial function. Additionally, these data suggest potentially different mechanisms of action related to low nitrate BRS and organic nitrate PETN.

Carbon Tetrachloride Poisoning

1945 ◽  
Vol 97 (1) ◽  
pp. 39-44
Author(s):  
S. M. Dillenberg ◽  
C. M. Thompson
Keyword(s):  
Carbon Tetrachloride ◽  
Carbon Tetrachloride Poisoning
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