Liver activity

Liver Activation of glycogen synthesis Activation of glycogen synthase (GS) Inactivation of glycogen synthase kinase 3 (GSK3) through phosphorylation by Akt... 

Medium-chain acyl-CoA synthetase, which is present within the mitochondrial matrix of the liver, activates fatty acids containing from four to ten carbon atoms. Medium-chain length fatty acids are obtained mainly from triacylglycerols in dairy products. However, unlike long-chain fatty acids, they are not esterified in the epithelial cells of the intestine but enter the hepatic portal vein as fatty acids to be transported to the liver. Within the liver, they enter the mitochondria directly, where they are converted to acyl-CoA, which can be fully oxidised and/or converted into ketone bodies. The latter are released and can be taken up and oxidised by tissues. 

Diazepam Status epilepticus-Epilepsy, all forms- 97 to 99 Liver, active metabolites... 

Important limitations of the PBPK approach are realized for class 3 and 4 compounds with significant active distribution/absorption processes, where biliary elimination is a major component of the elimination process or where the assumptions of flow-limited distribution and well mixed compartments are not valid and permeability-limited distribution is apparent. These drawbacks could be addressed by the addition of permeability barriers for some tissues and by the incorporation of a more complex liver model which addresses active uptake into the liver, active efflux into the bile, biliary elimination and enterohepatic recirculation. However, this improvement to current methodologies requires the availability of the appropriate input data for quantification of the various processes involved as well as validation of the corresponding in vitro to in vivo scaling approaches. 

Clarithromycin is readily and rapidly absorbed after oral administration and is metabolized significantly in liver. Active metabolite is excreted by kidney and other routes. 

Most of the radioactivity of the liver was recovered from the phosphate fraction after TCA treatment. Although the radioactivity recovered from total hepatic lipids increased up to 2-3 hours post-dosing, total hepatic lipids represented a maximum of only 1.4-3% of the administered dose of 32P. Lipids were also extracted from the microsomal fraction of the liver homogenate at the 4- and 10-hour sacrifices (n=4 for each). Total radioactivity of hepatic microsomal lipid significantly increased (p<0.025 n=4) between 4 and 10 hours post-dosing, whether expressed as percent of total liver activity (increased from about 2.7% to 4.1%) or as a percent of total 32P administered (increased from about 1.1% to 1.9%)... 

Fig. 21.2 Major effects of AMPK activation on numerous tissues. AMPK plays a key role in regulating whole body energy storage and expenditure. In hypothalamus, AMPK is involved in regulation of satiety and food intake. Activation of AMPK in the hypothalamus increases food intake, whereas inhibition decreases intake. In peripheral tissues such as skeletal muscle and liver, activation of AMPK increases energy expenditure by stimulating mitochondrial genesis and energy substrate utilization. AMPK also regulates lipolysis in adipose tissue and insulin secretion in pancreas.

System Injection site activity at 3d < initial dose) Whole body activity at 3d ( initial dose) Peak liver activity (% initial dose)... 

Potentially serious side-effects of azathioprine that are dose- and duration-dependent are haematological (leukopenia and thrombocytopenia) and gastrointestinal. Azathioprine is metabolized to 6-mercaptopurine, and both compounds are rapidly eliminated from blood and oxidized in red cells and liver. Activation of 6-mercaptopurine occurs via hypoxanthine-guanine phosphoribosyl-transferase. 6-Mercaptopurine is inactivated by thiopurine S-methyltransferase and by xanthine oxidase. 

Another forefront technique to improve the function of the stratum corneum and enhance barrier repair in dry skin is the use of epidermal differentiation. A number of hormone receptors for epidermal differentiation have been identified. This family of receptors includes retinoic acid receptors, the steroid receptors, the thyroid receptors, the Vitamin D receptors, the peroxisome proliferator-activated receptors, the farnesol-activated receptors, and the liver-activated receptors. It is reported that these transcription factors bind their respective ligands and regulate many of the aspects of cellular proliferation and differentiation. Examples of ligands for the last three transcription factors are fatty acids for the peroxisome proliferator-activated receptor, famesol for the farnesol-activated receptor, and hydroxylated cholesterol derivatives for the liver-activated receptor. The stimulation of epidermal differentiation stimulated the synthesis of involucrin, filaggrin, and the enzymes of the ceramide synthesis pathway (74). 

HBIG Hepatitis-B immunoglobulin LAP Liver active protein... 

Some methods have used a combination of techniques to improve specificity. These classic measurements for BAP are usually technically complicated and labor-intensive, imprecise, insensitive, and inaccurate. Of these techniques, heat denaturation and WGA precipitation have been used most frequently. Heat denaturation has been criticized because of its irreprodudbility or variability. WGA precipitation has been criticized because WGA does not precipitate all BAP from pagetic sera or from tire SaOS-2 osteosarcoma cell line and fails to completely separate bone and liver activity. ... 

Effect (Decreases in Increases PPARa Triglycerides or in Liver Activation VLDL-Triglycerides) Weight... 

Johnson, B.T. 1992. Rainbow trout liver activation systems with the Ames mutagenicity test. Environ. Toxicol. Chem. 9 1183-1192. 

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