WordNet

a tiny granule in the cytoplasm that is where protein synthesis takes place under the direction of mRNA
of or relating to microsomes

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/01/19 17:39:51」(JST)

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In cell biology, microsomes are vesicle-like artifacts re-formed from pieces of the endoplasmic reticulum (ER) when eukaryotic cells are broken-up in the laboratory; by definition, microsomes are not ordinarily present in living cells.^[1]

Microsomes can be concentrated and separated from other cellular debris by differential centrifugation. Unbroken cells, nuclei, and mitochondria sediment out at 10,000g, whereas soluble enzymes and fragmented ER, which contains cytochrome P450 (CYP), remain in solution (g is the Earth's gravitational acceleration). At 100,000g, achieved by faster centrifuge rotation, ER sediments out of solution as a pellet but the soluble enzymes remain in the supernatant. In this way, cytochrome P450 in microsomes is concentrated and isolated. Microsomes have a reddish brown color, due to the presence of the iron-containing co-factor, heme (haem), in the P450s. P450s are highly abundant in livers of rats, mice and humans.

Microsomes are a valuable tool for investigating the metabolism of compounds (enzyme inhibition, clearance and metabolite identification) and for examining drug-drug interactions by in vitro-research. Researchers often select microsome lots based on the enzyme activity level of specific CYPs. Some lots are available to study specific populations (example: lung microsomes from smokers or non-smokers) or divided into classifications to meet target CYP activity levels for inhibition and metabolism studies.

References

^ Voet, Donald; Voet, Judith G. (2004). Biochemistry (3rd ed.). Wiley. p. 1309. ISBN 0-471-19350-X.

External links

MeSH A11.284.835.540
The use of microsomes to measure clearance The performance of in vitro microsomal clearance studies including analysis of the data.

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English Journal

Metabolomics reveals the metabolic map of procainamide in humans and mice.

Li F, Patterson AD, Krausz KW, Dick B, Frey FJ, Gonzalez FJ, Idle JR.SourceLaboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States.
Biochemical pharmacology.Biochem Pharmacol.2012 May 15;83(10):1435-44. Epub 2012 Feb 24.
Procainamide, a type I antiarrhythmic agent, is used to treat a variety of atrial and ventricular dysrhythmias. It was reported that long-term therapy with procainamide may cause lupus erythematosus in 25-30% of patients. Interestingly, procainamide does not induce lupus erythematosus in mouse model
PMID 22387617

Verapamil does not modify catalytic activity of CYP450 in rainbow trout after long-term exposure.

Burkina V, Zamaratskaia G, Randak T, Li ZH, Fedorova G, Pickova J, Zlabek V.SourceUniversity of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zatisi 728/II, Vodnany 389 25, Czech Republic.
Ecotoxicology and environmental safety.Ecotoxicol Environ Saf.2012 May;79:148-52. Epub 2012 Jan 14.
Little is known about the effects of the cardiovascular drug verapamil (VRP) on metabolic processes in fish. Most calcium channel blockers including VRP are metabolized by cytochrome P450 (CYP450) enzymes. In this study we investigated the in vivo effect of VRP on some CYP450-mediated reactions in j
PMID 22244749

Japanese Journal

Characterization of Coumarin-Specific Prenyltransferase Activities in Citrus limon Peel

MUNAKATA Ryosuke,INOUE Tsuyoshi,KOEDUKA Takao [他],SASAKI Kanako,TSURUMARU Yusuke,SUGIYAMA Akifumi,UTO Yoshihiro,HORI Hitoshi,AZUMA Jun-ichi,YAZAKI Kazufumi
Bioscience, biotechnology, and biochemistry 76(7), 1389-1393, 2012-07-23
… In this study, we detected both O- and C-prenyltransferase activities of coumarin substrates in a microsome fraction prepared from lemon (Citrus limon) peel, where large amounts of prenylated coumarins accumulate. …
NAID 10030982292

Benzofuran Derivatives Inhibit 11β-Hydroxysteroid Dehydrogenase Type 1 Activity in Rat Adipose Tissue

Kiyonaga Daisuke,Tagawa Noriko,Yamaguchi Yuko [他],Wakabayashi Midori,Kogure Toshiaki,Ueda Masafumi,Miyata Okiko,Kobayashi Yoshiharu
Biological and Pharmaceutical Bulletin 35(8), 1275-1280, 2012
Excess glucocorticoids promote visceral obesity and insulin resistance. The main regulator of intracellular glucocorticoid levels are 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which converts …
NAID 130001872138

Synthesis and Biological Activities of 1α,4α,25- and 1α,4β,25-Trihydroxyvitamin D₃ and Their Metabolism by Human CYP24A1 and UDP-Glucuronosyltransferase

Sawada Daisuke,Tsukuda Yuya,Yasuda Kaori [他],Sakaki Toshiyuki,Saito Hiroshi,Takagi Ken-ichiro,Takenouchi Kazuya,Chen Tai C.,Reddy G. Satyanarayana,Kittaka Atsushi
Chemical and Pharmaceutical Bulletin 60(10), 1343-1346, 2012
A previous report has demonstrated the existence of a C4-hydroxylated vitamin D2 metabolite in serum of rats treated with pharmacological doses of vitamin D2. However, the biological significance and …
NAID 130001852369

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★リンクテーブル★

リンク元	「ミクロソーム」「マイクロソーム」「ミクロゾーム」「microsomal」「顆粒体」
拡張検索	「antibody to liver-kidney microsomes」「liver kidney microsome antibody」「microsome test」