Identification of Novel Human Cryogen and the Mechanism of Hypothermia

新型人体冷冻剂的鉴定及低温机制

• 批准号: 14370023
• 负责人: SHIDO Osamu
• 金额: $ 5.7万
• 依托单位: Shimane University, School of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14370023/
• 关键词: hypothermia; endogenous cryogen; thermogenic threshold; thermoregulation; electrophoresis; mass spectrometr; 血清タンパク質; 低体温症; イオン交換クロマトグラフィ

We experienced a hypothermic patient, i.e., a young female who suffered from severe hypothermia in a cool environment. Although various medical and physiological tests were performed, we failed to end any abnormalities responsible for hypothermia. According to thermoregulatory function tests, it appears that the threshold core temperatures for cold-defense responses of the patient shifted to extremely low levels. When the patient's serum was injected into the peritoneal cavity of rats, profound hypothermia was induced. Thus, we speculated that there were yet unidentified cryogenic substance(s) in the patient serum, and hence attempted to identify the substance(s). The patient's serum was divided into 4 fractions according to their molecular sizes, i.e., below 10kDa, 10〜30kDa, 30〜100kDa and more than 100kDa, using various types of filtration tubes and membranes. The intraperitoneal injections of the third fraction (30〜100kDa) produced clear hypothermia in rats, while the other fractions did not. Since the fraction includes a large amount of serum albumin, we separated patients' serum into two fractions, albumin rich and free fractions, with a commercial column for affinity chromatography. when albumin rich fraction was injected into rats, it produced significant hypothermia. Gel electrophoresis of the albumin rich fraction showed the presence of bands which were not seen in the serum of healthy controls. In a preliminary study, one of the bands was taken and directly analyzed by mass spectrometry. According to the search of human genome database, a fragment of certain protein was included in the band. It was speculated that the patient may have produced, unknown cryogenic substance(s) which might be degradation products from serum proteins physiologically existing in human serum.

我们遇到了一个低温症患者，即一个年轻的女性，她在凉爽的环境中遭受了严重的低温症。尽管进行了各种医学和生理测试，但我们未能消除任何导致体温过低的异常情况。根据体温调节功能测试，患者的冷防御反应的阈值核心温度似乎转移到极低的水平。将患者血清注射到大鼠腹腔，引起深度低温。因此，我们推测患者血清中存在尚未识别的低温物质，并试图鉴定该物质。将患者血清按分子大小分为10kDa以下、10 ~ 30kDa、30 ~ 100kDa、100kDa以上4组，采用不同类型的过滤管和过滤膜。腹腔注射第三组分（30 ~ 100kDa）对大鼠产生明显的低体温，而其他组分无明显的低体温。由于该馏分中含有大量的血清白蛋白，我们将患者的血清分为富白蛋白馏分和游离白蛋白馏分两部分，使用商业柱进行亲和层析。富白蛋白组分注射大鼠后，产生明显的低体温。富白蛋白部分的凝胶电泳显示存在健康对照血清中未见的条带。在初步研究中，取其中一条谱带，用质谱法直接分析。根据对人类基因组数据库的检索，该条带中包含了某种蛋白质的片段。据推测，患者可能产生了未知的低温物质，这些物质可能是生理上存在于人血清中的血清蛋白的降解产物。

项目成果

Shido et al.: "A young female patient suffering from hypothermia in a cool environment."Shimane J.Med.Sci.. 20. 45-51 (2002)

Shido 等人：“一名年轻女性患者在凉爽的环境中患有体温过低。”Shimane J.Med.Sci.. 20. 45-51 (2002)

Shido O., et al.: "A young female patient suffering from hypothermia in a cool environment."Shimane J.Med.Sci.. 20. 45-51 (2002)

Shido O., et al.：“一名年轻女性患者在凉爽的环境中患有体温过低。”Shimane J.Med.Sci.. 20. 45-51 (2002)