辣椒和疼痛的科学

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辣椒和疼痛的科学

The Science of Peppers and Pain
Posted by Jacob Goldstein

There’s a biological reason we say spicy food is hot: The chemical that gives peppers their punch targets the same nerve-cell receptors as high temperatures.

David Julius, the biochemist who uncovered the connection, hopes the insight could help develop new drugs to block pain, Peter Landers reports today on WSJ.com.

Industry has picked up on his work. Merck is in mid-stage human trials of a drug, licensed from Neurogen, designed to treat dental pain. Pfizer and GlaxoSmithKline are working on similar drugs, though it will likely be five or 10 years before any of the medicines has a shot at making it to the market.

Julius and his colleagues published a seminal study in Nature 10 years ago, demonstrating that capsaicin, the active ingredient in chili peppers, works on the same receptor as high temperatures to open up nerve cells, allowing ions to rush in and send a pain message to the brain. (The abstract of that study is here.)

They went on to show that mice genetically engineered to lack the receptor drank water laced with capsaicin; regular mice who drank the water “rubbed their snouts vigorously and avoided further consumption,” wrote Julius et al.

Later, Julius’s group was one of two scientific teams to discover that menthol activated the same nerve-cell receptor as cool temperatures. Normal mice generally prefer to stand on warm surfaces. But in a paper published earlier this year in Nature, Julius and his colleagues showed that mice engineered to lack the menthol receptor didn’t mind standing on a plate cooled to 50 degrees.
辣椒和疼痛关系的研究
我们通常说辛辣食物是热的，一般是生理原因引起的：辛辣粉中所含有的化学物质作用人体的某个部位，这是神经细胞接受高温信号的地方。David Julius, 一个生物化学家，发现了这种联系，他希望这个发现能去帮助发明新的阻止疼痛的药物，Peter Landers今天在WSJ.com.网上报道。
企业已经开始继续他的工作。Merck公司正出于中试阶段，并得到Neurogen许可，计划被设计成治疗牙痛。辉瑞和葛兰素史克正在研发类似的药物，尽管那可能要5年或10年，在任何一个类似药物被推向市场之前。
Julius和他的同事们在10年前自然杂志上发表了一篇初期的研究，结果显示辣椒碱，存在于红辣椒中的活性成分，它起作用的接受器与人们在高温下打开的神经细胞接受器相同，允许离子进入并且把疼痛信息传递给大脑。（研究的摘要在这里。）他们计划应用基因工程去克隆一种老鼠，它缺少高温感受器，让它喝含有辣椒碱的水；一般地说，正常的老鼠喝这种水后，会不断地摩擦鼻子，避免进一步的疼痛。
之后，Julius的小组是两个科研小组之一，他们发现薄荷醇作用于神经细胞接受器能起降温的作用。正常的老鼠一般喜欢处于温暖的一边。但是，在今年自然杂志上早期发表的一篇文章中，Julius和他的同事们发现，缺少接受器的转基因小鼠不是处于凉爽的一边，而是位于高达50度的地方。