NATURE OF THE WATER-SOLUBLE ESTROGEN METABOLITES FORMED BY RAT LIVER IN VITRO

1965 ◽  
Vol 43 (10) ◽  
pp. 1774-1776 ◽  
Author(s):  
P. H. Jellinck ◽  
Catherine Lazier ◽  
Mary L. Copp
Keyword(s):  
Rat Liver ◽  
Water Soluble ◽  
Estrogen Metabolites

scholarly journals Polyethylene Glycol Preconditioning: An Effective Strategy to Prevent Liver Ischemia Reperfusion Injury

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Bejaoui ◽  
Eirini Pantazi ◽  
Maria Calvo ◽  
Emma Folch-Puy ◽  
Anna Serafín ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Rat Liver ◽  
Ischemia Reperfusion Injury ◽  
Tissue Injury ◽  
Ischemia Reperfusion ◽  
Water Soluble ◽  
Effective Strategy ◽  
Sprague Dawley ◽  
Hepatic Ischemia

Hepatic ischemia reperfusion injury (IRI) is an inevitable clinical problem for liver surgery. Polyethylene glycols (PEGs) are water soluble nontoxic polymers that have proven their effectiveness in variousin vivoandin vitromodels of tissue injury. The present study aims to investigate whether the intravenous administration of a high molecular weight PEG of 35 kDa (PEG 35) could be an effective strategy for rat liver preconditioning against IRI. PEG 35 was intravenously administered at 2 and 10 mg/kg to male Sprague Dawley rats. Then, rats were subjected to one hour of partial ischemia (70%) followed by two hours of reperfusion. The results demonstrated that PEG 35 injected intravenously at 10 mg/kg protected efficiently rat liver against the deleterious effects of IRI. This was evidenced by the significant decrease in transaminases levels and the better preservation of mitochondrial membrane polarization. Also, PEG 35 preserved hepatocyte morphology as reflected by an increased F-actin/G-actin ratio and confocal microscopy findings. In addition, PEG 35 protective mechanisms were correlated with the activation of the prosurvival kinase Akt and the cytoprotective factor AMPK and the inhibition of apoptosis. Thus, PEG may become a suitable agent to attempt pharmacological preconditioning against hepatic IRI.

scholarly journals A fraction derived from brewer's yeast inhibits cholesterol synthesis by rat liver preparations in vitro

1991 ◽  
Vol 65 (2) ◽  
pp. 285-299 ◽  
Author(s):  
E. S. Holdsworth ◽  
D. V. Kaufman ◽  
E. Neville
Keyword(s):  
Rat Liver ◽  
Plasma Lipids ◽  
Normal Diet ◽  
Water Soluble ◽  
Sterol Synthesis ◽  
Brewer’S Yeast ◽  
Nicotinamide Riboside ◽  
Brewer's Yeast

Brewer's yeast was grown on a defined medium containing tracer51Cr with or without added chromium. The two batches of yeast contained 10 μg/g (high-Cr) or 80 ng/g (low-Cr). Extracts were prepared and fractionated. A third batch of yeast (third batch) was grown with added Cr, and fractionated. Rats were reared on either rat cubes (normal diet) or on a low-Cr diet (low-Cr), or on rat cubes with added cholestyramine (cholestyramine diet). Preparations of rat liver, both cell-free and intact hepatocytes, incorporated acetate-carbon into fatty acids and cholesterol. These processes were inhibited by a yeast fraction containing small, neutral, water-soluble compounds. The degree of inhibition was the same whether the liver came from normal rats or rats fed on the low-Cr diet. Similarly the inhibitory effect was found with identical amounts of extracts from low- or high-Cr yeasts. Therefore, Cr compounds do not appear to account for the inhibitory effects of brewer's yeast. Use of other substrates indicated that the site of inhibition of sterol synthesis was apparently between acetyl-CoA and mevalonate. One inhibitory substance was isolated from yeast and was found to be nicotinamide riboside. This may have been produced from NAD(P) during the preparation of yeast extracts, and it may be produced from dietary yeast supplements during digestion in vivo. Nicotinamide riboside may be partly responsible for the reported effects of yeast supplements on plasma lipids in humans.

scholarly journals Binding in vitro to rat liver receptors does not correlate with activities in vivo of bovine somatotropin. Use of chemically modified derivatives as probes

1984 ◽  
Vol 224 (2) ◽  
pp. 535-540 ◽  
Author(s):  
L P Roguin ◽  
J M Delfino ◽  
N Vita ◽  
A C Paladini
Keyword(s):  
Rat Liver ◽  
Binding Sites ◽  
Specific Binding ◽  
The Body ◽  
Water Soluble ◽  
Bovine Somatotropin ◽  
Isolated Cells ◽  
Carboxylate Groups

Bovine somatotropin with an increasing number of its carboxylate groups modified by reaction with glycine methyl ester in the presence of a water-soluble carbodi-imide was tested for its activity in different bioassays. Only those derivatives which were known to be active in the body-weight-increase bioassay were able to compete with 125I-labelled bovine somatotropin for their specific binding sites in vivo. No difference was found in the rate of clearance of a poorly active derivative as compared with that of native somatotropin. In contrast, both active and inactive derivatives were found to be equally effective in displacing the tracer from its binding sites present in isolated cells and membrane preparations from rat liver. These results suggest that the liver somatogenic receptors studied in vitro are less discriminating than those detected in vivo.

scholarly journals Metabolism of [14C]diethylstilboestrol epoxide by rat liver in vitro

1980 ◽  
Vol 185 (1) ◽  
pp. 129-137 ◽  
Author(s):  
P H Jellinck ◽  
J H Bowen
Keyword(s):  
Rat Liver ◽  
Microsomal Fraction ◽  
Water Soluble ◽  
Immature Rat ◽  
Epoxide Hydratase ◽  
New Type ◽  
Liver Microsomal Fraction ◽  
Harmful Effects

1. The trans-epoxide of diethylstilboestrol and its pinacolone were synthesized chemically and the pinacolone shown to be formed from the epoxide by a non-enzymic process. 2. [14C]Diethylstiboestrol epoxide was converted by rat liver microsomal fraction into 4'-hydroxypropiophenone by a new type of cleavage reaction involving mono-oxygenase. Conditions for the formation of this metabolite and also water-soluble products were investigated together with the effect of inhibitors. A sex-difference in the conversion of diethylstilboestrol epoxide into 4'-hydroxypropiophenone and to polar and water-soluble products was observed. 3. Diethylstilboestrol epoxide was found to be a relatively stable compound that did not form a glutathione conjugate readily without further microsomal activation. A purified preparation of epoxide hydratase did not enhance its rate of conversion into the pinacolone. 4. Diethylstilboestrol epoxide was found to have about one-tenth the oestrogenic activity of diethylstilboestrol as measured by the increase in uterine weight or the induction of peroxidase in immature rat uteri. It was inactive as a mutagen when tested for its ability to inhibit bacteriophage phi X174 DNA viral replication. 5. The possible role of diethylstilboestrol epoxide as an intermediate in the metabolism of diethylstilboestrol and in mediating the harmful effects of this synthetic estrogen is discussed.

Effect of X-irradiation on gene expression of rat liver chemokines: in vivo and in vitro studies

2008 ◽  
Vol 46 (01) ◽  
Author(s):  
F Moriconi ◽  
H Christiansen ◽  
H Christiansen ◽  
N Sheikh ◽  
J Dudas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rat Liver ◽  
In Vitro Studies ◽  
X Irradiation

Controlled Release of Metformin Hydrochloride I. In vitro Release from Physical Mixture Containing Xanthan Gum as Hydrophilic Rate Retarding Polymer

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza
Keyword(s):  
Controlled Release ◽  
Xanthan Gum ◽  
In Vitro Release ◽  
Correlation Coefficients ◽  
High Ratio ◽  
Water Soluble ◽  
Metformin Hydrochloride ◽  
Model Drug ◽  
Very High

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

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