blood urea nitrogen

血中尿素窒素 BUN

WordNet

1. smear with blood, as in a hunting initiation rite, where the face of a person is smeared with the blood of the kill
2. temperament or disposition; "a person of hot blood"
3. people viewed as members of a group; "we need more young blood in this organization"
4. the fluid (red in vertebrates) that is pumped through the body by the heart and contains plasma, blood cells, and platelets; "blood carries oxygen and nutrients to the tissues and carries away waste products"; "the ancients believed that blood was the sea
5. a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living tissues (同)N, atomic number 7
6. the chief solid component of mammalian urine; synthesized from ammonia and carbon dioxide and used as fertilizer and in animal feed and in plastics (同)carbamide

PrepTutorEJDIC

1. 『血』,『血』液 / 流血(bloodshed);殺人 / 気質,気性,血気,血潮 / 『血統』,血縁(kinship);生まれ,家柄;《the~》王家の血統 / (人種・出身国の)系 / 〈人〉‘に'初めての経験をさせる / 〈猟犬〉‘に'初めて獲物を血を味わわせる
2. 『窒素』(気体元素;化学記号は『N』)
3. 尿素(にょうそ)
4. 純血の,純種の / 《複合語を作って》「…の血(性質)を持った」の意を表す

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2019/06/06 11:16:27」(JST)

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[Wiki en表示]

"BUN" redirects here. For other uses, see Bun (disambiguation).

Blood urea nitrogen
Medical diagnostics
Urea
MeSH	D001806
LOINC	6299-2, 59570-2, 12961-9, 12963-5, 12962-7

Blood urea nitrogen (BUN) is a medical test that measures the amount of urea nitrogen found in blood. The liver produces urea in the urea cycle as a waste product of the digestion of protein. Normal human adult blood should contain between 7 to 20 mg/dL (2.5 to 7.1 mmol/L) of urea nitrogen. Individual laboratories will have different reference ranges as the assay used can vary between laboratories.

Interpretation

BUN is an indication of renal (kidney) health. The normal range is 1.8–7.1 mmol/L or 6–20 mg/dL.

The main causes of an increase in BUN are: high protein diet, decrease in glomerular filtration rate (GFR) (suggestive of renal failure) and in blood volume (hypovolemia), congestive heart failure, gastrointestinal hemorrhage, fever, and increased catabolism. Hypothyroidism can cause both decreased GFR and hypovolemia, but BUN-to-creatinine ratio has been found to be lowered in hypothyroidism and raised in hyperthyroidism.

The main causes of a decrease in BUN are severe liver disease, anabolic state, and syndrome of inappropriate antidiuretic hormone.

Reference ranges for blood tests, comparing urea (yellow at right) to other blood constituents

Another rare cause of a decreased BUN is ornithine transcarbamylase deficiency, which is a genetic disorder inherited in an X-linked recessive pattern. OTC deficiency is also accompanied by hyperammonemia and high orotic acid levels.

Units

BUN (urea-N) is mg/dL in the United States, Mexico, Italy, Austria, and Germany. Elsewhere, the concentration of urea is reported as mmol/L, generally depending on the lab.

BUN (urea-N) SI unit is mmol/L

BUN [mmol/L] = BUN [mg/dL] * 0.3571

To convert from mg/dL of blood urea nitrogen to mmol/L of urea, multiply by 0.357 (each molecule of urea having two nitrogens, each of molar mass 14g/mol) (BUN is the mass of nitrogen within urea/volume, not the mass of urea)

Urea [mmol/L] = BUN [mg/dL of nitrogen] x 10 [dL/L] / 14x2 [mg N/mmol urea] (the mass of nitrogen within urea is used)

convert BUN to urea in mg/dL by using following formula:

Urea [mg/dL]= BUN [mg/dL] * 2.14

(conversion factor derived by: MW of urea = 60, MW of urea nitrogen = 14x2 => 60/28 = 2.14)

factor = 1 for conversions in mmol (1 mole N₂ = 2 moles N per mole of urea):

BUN [mmol/L]= urea [mmol/L]

See also

• Kt/V
• Urea reduction ratio
• Urine urea nitrogen
• Standardized Kt/V

UpToDate Contents

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• 1. 腎機能の評価 assessment of kidney function
• 2. 尿素サイクル障害：臨床的特徴および診断 urea cycle disorders clinical features and diagnosis
• 3. 成人における体液量減少の病因、臨床症状、および診断 etiology clinical manifestations and diagnosis of volume depletion in adults
• 4. 急性腎障害（急性腎不全）における腎前性疾患および急性尿細管壊死の病因および診断 etiology and diagnosis of prerenal disease and acute tubular necrosis in acute kidney injury acute renal failure
• 5. 尿毒症毒素 uremic toxins

English Journal

• Metabolomic evaluation of Euphorbia pekinensis induced nephrotoxicity in rats.

• Liu Z1,2, Zeng Y2,3, Hou P2,4.
• Pharmaceutical biology.Pharm Biol.2018 Dec;56(1):145-153. doi: 10.1080/13880209.2018.1435697.
• PMID 29421944

• Evaluation of the 1B Equation to Estimate Glomerular Filtration Rate in Pediatric Patients with Cancer.

• Jeong TD1, Kim J2, Lee W2, Chun S2, Hong KS1, Min WK3.
• Annals of laboratory medicine.Ann Lab Med.2018 May;38(3):261-265. doi: 10.3343/alm.2018.38.3.261.
• PMID 29401562

• Protective action of Crateva nurvala Buch. Ham extracts against renal ischaemia reperfusion injury in rats via antioxidant and anti-inflammatory activities.

• Choucry MA1, Khalil MNA2, El Awdan SA3.
• Journal of ethnopharmacology.J Ethnopharmacol.2018 Mar 25;214:47-57. doi: 10.1016/j.jep.2017.11.034. Epub 2017 Dec 5.
• PMID 29217496

Japanese Journal

• Risk Stratification of Acute Kidney Injury Using the Blood Urea Nitrogen/Creatinine Ratio in Patients With Acute Decompensated Heart Failure

• Takaya Yoichi,Yoshihara Fumiki,Yokoyama Hiroyuki [他]
• Circulation journal : official journal of the Japanese Circulation Society 79(7), 1520-1525, 2015-07
• NAID 40020502357

• ウサギはなぜ糞を食べる？

• 坂口 英
• 岡山大学農学部学術報告 104, 23-34, 2015-02-01
• … The source of nitrogen is easily obtained as urea transfered from the blood flow. … As a result, the amount of cecotrophy increases, and the percentage of nitrogen accumulation in the body tends to increase. …
• NAID 120005537570

• Change in soluble epoxide hydrolase (sEH) during cisplatin-induced acute renal failure in mice

• Hashimoto Terumasa,Fang Yang-Il,Ohata Hisayuki,Honda Kazuo
• The Journal of Toxicological Sciences 40(4), 451-457, 2015
• … The down-regulation occurred prior to the elevation of blood urea nitrogen (BUN) and tumor necrosis factor-α (TNF-α) gene expression or at treatment with low dose cisplatin. …
• NAID 130005087444

Related Pictures

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★リンクテーブル★

リンク元	「血液尿素窒素」「尿素窒素」「BUN」
関連記事	「nitrogen」「blood」

「血液尿素窒素」

　　[★]

英

blood urea nitrogen BUN

同

血中尿素窒素、血清尿素窒素 serum urea nitrogen SUN ←最近は、ほとんどの施設で血清をサンプルとしているので、こっちを使うべき

関

BUN/Cr比、尿素窒素、クレアチニン

[show details]

血液尿素窒素 : 約 30,200 件
血中尿素窒素 : 約 9,050 件
血清尿素窒素 : 約 20,600 件

• 血中残余窒素の半分が尿素。腎障害の時に増加する(医学略語辞典)

基準値

• 8-20mg/dl(流れが分かる実践検査マニュアル上巻 p.12)
• 7-20mg/dl(HIM A.)

検査値の異常 (異常値の出るメカニズム第5版 p.144)

BUN上昇

• 1. 組織の異化亢進

• 外科的大手術、体内への出血、異型輸血、悪性腫瘍、飢餓時、高熱、高度熱傷、アジソン病のクリーゼ、糖尿病性アシドーシス、甲状腺機能亢進症、膵臓壊死、重症感染症

• 2. 蛋白摂取量の増加
• 3. 消化管出血

• 赤血球・血漿蛋白が腸管内で分解　→　分解されて生成するNH₃が小腸で吸収される　→ BUN↑

• 4. 腎血流量の減少

• 重症心不全、ショック

• 5. 腎障害

• 尿素排泄機能が低下

• 6. 尿路の閉塞

• 腎後性に尿排泄が阻害されると尿素が血液中にうっ滞する。

「尿素窒素」

　　[★]

英

urea nitrogen UN

同

血中尿素窒素 blood urea nitrogen BUN

関

尿素、ウレアーゼ、クレアチニン、残余窒素

意義

• 血中の尿素
• 尿素は肝臓で尿素サイクルによって産生される。

尿素窒素を構成する要素 LAB

• 産生：腎前性因子(食事蛋白摂取量、組織崩壊、胃腸管出血)、循環血液量の異常(脱水、血液濃縮)
• 排泄：腎性因子：腎機能
• その他：チアジド系利尿薬、エタクリン酸、テトラサイクリン系抗菌薬(腎障害作用、蛋白異化作用を有する)で中等度上昇。成長ホルモンやタンパク質同化ホルモンにより低下。

基準値

• 8-20 mg/dL (QB)

単位の変換：1 mg/dL = 10 x 10^-3 g/L = 10^-2 / 28 mol/L = 0.0003751 mol/L = 0.3751 mmol/L

N2 = 28 g/L

判別(検査値の本より)

• 3g/日以下(減少)

• [高頻度]肝不全(肝硬変末期など)、高度腎不全、低蛋白食、妊娠
• [可能性]飢餓

• 15g/日以上(増加)

• [高頻度]高蛋白食、蛋白異化の亢進する病態(悪性腫瘍、感染、外傷、手術など)
• [可能性]コルチコステロイド、利尿薬、テトラサイクリンなどの薬物投与

「BUN」

　　[★] 血液尿素窒素 blood urea nitrogen

「nitrogen」

　　[★]

• n.

• 窒素

関

N、N2、nitric

　 　

「blood」

　　[★] 血液