L-组氨酸完全抑制生长，其对活力的影响与 FLO11 的表达呈负相关。 L-组氨酸对S288c和Δflo11菌株的存活能力没有影响。 L-组氨酸极大地抑制了弗洛氏酵母的空气-液体生物膜形成和聚硅氧烷痕迹，而FLO11基因的改变水平不受影响。此外，L-组氨酸可以改变弗洛酵母细胞壁中脂质和几丁质的含量[1]。

L-组氨酸（100 mg/kg）完全抑制硫代乙酰胺治疗的脑水肿[2]。 L-组氨酸饮食组60%的脑水肿是由于强K+刺激下下丘脑释放组胺引起的。然而，L-组氨酸饮食对其他单胺没有影响，也不会改变该物质的浓度。 L-组氨酸饮食组在整个明暗箱测试表现期间都停在灯箱中，而在旷场测试表现期间，他们停在中心区域。这表明 L-组氨酸饮食组可能会导致焦虑样行为 [3]。

Absorption, Distribution and Excretion
Absorbed from the small intestine via an active transport mechanism requiring the presence of sodium.
ESSENTIAL AMINO ACIDS ARE TRANSFERRED TO FETUS AGAINST A CONCN GRADIENT &, IN THE CASE OF HISTIDINE, NATURAL L-ISOMER HAS BEEN SHOWN TO CROSS SEVERAL TIMES AS FAST AS THE D-ISOMER.

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Metabolism / Metabolites
PRODUCT OF OXIDATIVE DEAMINATION OR TRANSAMINATION OF L-HISTIDINE IS BETA-IMIDAZOLEPYRUVIC ACID; & PRODUCT OF DECARBOXYLATION IS HISTAMINE. HISTAMINE ENTERS OTHER PATHWAYS TO YIELD FURTHER METABOLIC PRODUCTS. /FROM TABLE/

Toxicity Summary
Since the actions of supplemental L-histidine are unclear, any postulated mechanism is entirely speculative. However, some facts are known about L-histidine and some of its metabolites, such as histamine and trans-urocanic acid, which suggest that supplemental L-histidine may one day be shown to have immunomodulatory and/or antioxidant activities. Low free histidine has been found in the serum of some rheumatoid arthritis patients. Serum concentrations of other amino acids have been found to be normal in these patients. L-histidine is an excellent chelating agent for such metals as copper, iron and zinc. Copper and iron participate in a reaction (Fenton reaction) that generates potent reactive oxygen species that could be destructive to tissues, including joints.
L-histidine is the obligate precursor of histamine, which is produced via the decarboxylation of the amino acid. In experimental animals, tissue histamine levels increase as the amount of dietary L-histidine increases. It is likely that this would be the case in humans as well. Histamine is known to possess immunomodulatory and antioxidant activity. Suppressor T cells have H2 receptors, and histamine activates them. Promotion of suppressor T cell activity could be beneficial in rheumatoid arthritis. Further, histamine has been shown to down-regulate the production of reactive oxygen species in phagocytic cells, such as monocytes, by binding to the H2 receptors on these cells. Decreased reactive oxygen species production by phagocytes could play antioxidant, anti-inflammatory and immunomodulatory roles in such diseases as rheumatoid arthritis.
This latter mechanism is the rationale for the use of histamine itself in several clinical trials studying histamine for the treatment of certain types of cancer and viral diseases. In these trials, down-regulation by histamine of reactive oxygen species formation appears to inhibit the suppression of natural killer (NK) cells and cytotoxic T lymphocytes, allowing these cells to be more effective in attacking cancer cells and virally infected cells.

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Toxicity Data
ORL-RAT LD₅₀ > 15000 mg/kg, IPR-RAT LD₅₀ > 8000 mg/kg, ORL-MUS LD₅₀ > 15000 mg/kg, IVN-MUS LD₅₀ > 2000 mg/kg

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Interactions
WARFARIN ALONE AT 5 MG/KG OF BAIT KILLED 37% OF ROOF RATS, BUT WHEN IN COMBINATION WITH L-HISTIDINE (40 MG/KG BAIT), ACTIVATED CLAY, CHARCOAL, & CARBON (10 G/KG BAIT) IT CAUSED, RESPECTIVELY, 100, 88, 75, & 63% MORTALITY OF RATS.

[1]. Bou Zeidan M, et al. L-histidine inhibits biofilm formation and FLO11-associated phenotypes in Saccharomyces cerevisiae flor yeasts. PLoS One. 2014 Nov 4;9(11):e112141.
[2]. Rama Rao KV, et al. Brain edema in acute liver failure: inhibition by L-histidine. Am J Pathol. 2010 Mar;176(3):1400-8.
[3]. Yoshikawa T, et al. Insufficient intake of L-histidine reduces brain histamine and causes anxiety-like behaviors in male mice. J Nutr. 2014 Oct;144(10):1637-41

Pharmacodynamics
Is found abundantly in hemoglobin; has been used in the treatment of rheumatoid arthritis, allergic diseases, ulcers and anemia. A deficiency can cause poor hearing.

C6H9N3O2

155.15

155.069

71-00-1

L-Histidine-15N3;1217456-12-6;L-Histidine-13C6,15N3 hydrochloride;L-Histidine dihydrochloride;6027-02-7

6274

Needles or plates
COLORLESS

1.4±0.1 g/cm3

458.9±35.0 °C at 760 mmHg

282 °C (dec.)(lit.)

231.3±25.9 °C

0.0±1.2 mmHg at 25°C

1.615

-1.26

92

3

4

3

11

151

1

C1=C(NC=N1)C[C@@H](C(=O)O)N

HNDVDQJCIGZPNO-YFKPBYRVSA-N

InChI=1S/C6H9N3O2/c7-5(6(10)11)1-4-2-8-3-9-4/h2-3,5H,1,7H2,(H,8,9)(H,10,11)/t5-/m0/s1

(2S)-2-amino-3-(1H-imidazol-5-yl)propanoic acid

Histidine NSC137773 NSC 137773 NSC-137773L-Histidine

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~20.83 mg/mL (~134.26 mM)
DMSO : ~1 mg/mL (~6.45 mM)

配方 1 中的溶解度: 25 mg/mL (161.13 mM) in PBS (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液; 超声助溶。

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请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。