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Related to Microsome: microsomal enzymes


(cell and molecular biology)
A fragment of the endoplasmic reticulum.
A minute granule of protoplasm.



a fragment in the endoplasmic network (bubbles about 1,000 angstroms diameter), formed when cells are destroyed during the homogenization of animal and plant tissues. The microsome fraction of the homogenate is isolated by differential centrifugation. There are two types of microsomes: smooth-surfaced and rough-surfaced (as a result of the distribution of ribosomes on the latter). Before the technique of separating cellular homogenates was perfected, the microsome fraction also included mitochondria.

References in periodicals archive ?
CYP2D6 is the principal cytochrome P450 responsible for the metabolism of histamine H1 antagonist promethazine in human liver microsomes.
450] contents were expressed as [eta]mol cytochrome/mg microsomal protein, glutathione S-transeferase activity was expressed as units/mg protein, NADPH cytochrome C-reductase activity was expressed as [eta]mol cytochrome C-reductase/mg protein/min, amidopyrine N-demethylase in liver microsomes was expressed as [micro]mol/min x kg liver sample, aniline-4-hydroxylase was expressed as [micro]mol/min/mg protein, and thiobarbituric acid reactive substances (TBARS) were expressed as [micro]mol TBARS/g tissue.
For kinetic studies, CYP2B6 and pooled human liver microsomes (HLMs) were incubated with BDE-47 (0-60 [mu]M).
Co-incubation of TBMEHP and T4 with rat hepatic microsomes resulted in a dose-dependent decrease in deiodinase activity (Figure 5).
Using this microsomal activation mixture, Mailing (1971) showed that dimethylnitrosamine was mutagenic in Salmonella in a liquid-suspension assay, resulting in the first version of what would later be called the Salmonellal mammalian microsome mutagenicity assay.
According to Celsis, InVitroCYP is the only microsome product on the market with substrate data reported at both Km and Vmax concentrations, providing researchers with maximum visibility for predictive performance and quality.
85-fold of increase of CYP2E1 activity and sustained loss almost half of HO-1 activity in rat liver microsomes.
Therefore, in this study, relative amount of midazolam and its metabolites are measured by high performance liquid chromatography (HPLC), as the indicating reaction for monitoring CYP3A activity in rat liver microsomes and plasma.
Good correlations have been observed for in vitro clearance measured with human microsomes or (cryopreserved) hepatocytes and in vivo clearance (Blanchard et al.
05-20 pmol), as well as 1 pmol of internal standard, were spiked into 100 [micro]g of control Sf9 cell microsomes and then processed as described above, for constructing calibration curves.
13) showed that ritonavir is metabolized by CYP 3A4 and CYP 3A5 at the same ratio, but indinavir is metabolized by CYP 3A4 than CYP 3A5 in human intestinal microsomes and expressed CYP 3A4/3A5.
1,2,4,5] AIH is divided into two types: Type 1 AIH is characterized by circulating antibodies to nuclei (ANA) or smooth muscle (ASMA) and Type 2 AIH is characterized by the presence of antibodies to liver or kidney microsomes (ALKM-1) and/or to a liver cytosol antigen (ALC-1).