Sökning: "PXR"
Visar resultat 1 - 5 av 12 avhandlingar innehållade ordet PXR.
1. Chemical mixtures and interactions with detoxification mechanisms and biomarker responses in fish
Sammanfattning : Several classes of anthropogenic chemicals are present as mixtures in the aquatic environment. However, information of how wildlife species, including fish, are affected by exposures to chemical mixtures is limited. LÄS MER
2. Studies on nuclear receptors involved in drug metabolism
Sammanfattning : The molecular basis for drug metabolism is starting to emerge as a result of cloning and characterization of a group of nuclear receptors that respond to drugs by transcriptional regulation of key genes encoding enzymes involved in metabolism of commonly used drugs. This thesis describes the identification and functional, as well as the structural, characterization of one of these receptors, the human pregnenolone activated receptor (hPAR, NR1I2) that also has been referred to as the pregnane X receptor (PXR) or the steroid and xenobiotic receptor (SXR) by others. LÄS MER
3. Cytochrome P450 in the rat brain : characterization and regulation
Sammanfattning : Cytochrome P450s (CYPs) are key enzymes in the metabolism of cholesterol and fatty acids and their derivatives in the body. In the adrenals and gonads these enzymes are involved in steroid hormone biosynthesis, in the liver in bile acid synthesis, in the kidney in synthesis of the calcitropic hormone, calcitriol, and in the cardiovascular system in synthesis of thromboxane A2, a potent inducer of vasoconstriction and platelet aggregation. LÄS MER
4. Determinants of ligand-induced nuclear receptor activation
Sammanfattning : The nuclear receptors (NRs) constitute a highly conserved superfamily of transcription factors restricted to metazoans. In general, these receptors are regulated by small lipophilic molecules such as steroids, thyroid hormones and retinoids and play an important role in cellular regulation. LÄS MER
5. Clinical studies of CYP3A4 and P-glycoprotein
Sammanfattning : In the field of pharmacokinetics, cytochrome P450 enzymes have been extensively studied. The CYP450 enzyme with the most drug substrates is CYP3A4, but despite its significance, administration of a specific substrate to subjects is required to determine its activity, by measuring the metabolic ratio. LÄS MER