VOA标准英语2010年-Blocking Pain at its Source

Research for new painkiller¹ finds inspiration in chili² peppers

Naomi Seck | Washington, DC 04 May 2010
 

Inspired by chili peppers, researchers are working toward a painkiller that could stop the brain from registering the presence of pain.

Related Links
Journal of Clinical Investigation³

Anyone who has ever had to recover from surgery or a serious injury was probably grateful for the powerful narcotics⁴ doctors prescribed to help ease the pain. But all these medications do is dull the brain's perception of pain.

Your brain registers pain through neurons, special cells that wind through the body. When you touch boiling water, for example, get a cut, or even exercise too much, a special receptor on the neuron is activated⁶, sending a signal to the brain — that hurts!.

This much scientists knew. However, they were not clear on how that receptor was activated when this kind of painful event occurred.

The chili pepper model

University of Texas researcher Kenneth Hargreaves says they got an important clue from chili peppers.

He explains that, while people think of the capsaicin from chili peppers as a spice, "it is actually a selective drug. It really produces its effects primarily by just activating⁷ the so-called capsaicin receptor."

When we eat chili peppers, we feel a burning sensation. That feeling is caused by the capsaicin molecules⁹ in the peppers activating the capsaicin receptors on our tongue — the more capsaicin, the hotter the pepper.

In the course of an entirely¹⁰ different experiment, Hargreaves and his team of researchers discovered that the skin produces its own capsaicin-like molecules, in response to pain.

"We took isolated¹¹ skin biopsies from laboratory mice, exposed those isolated skin biopsies to temperatures of 43 degrees or 48 degrees, and then we looked at what was being released from the skin under those conditions." Heat typically becomes painful at about 47 degrees Celsius¹².

When the skin samples were heated to 48 degrees, they produced this capsaicin-like molecule⁸ into a solution. Then, Hargreaves says, the researchers applied¹³ the solution to mice neurons; some with the capsaicin-receptor and some that had been genetically¹⁴ modified to eliminate that receptor.

"The ability of these substances to activate⁵ pain neurons was totally dependent upon capsaicin receptor," says Hargreaves.

A new approach to treating pain

Hargreaves says this is a huge discovery, one that could fundamentally change how doctors treat pain. "Now that we have discovered the endogenous capsaicin molecules, for the first time, we can block their synthesis and therefore we can treat pain at its cause."

Narcotics, the most powerful drugs currently available to fight pain, simply dull the brain's perception of it. But if a medication can block the capsaicin-like molecule from reaching the neuron, it could stop the brain from ever registering there was any pain to begin with.

Hargreaves and his team are already in the process of developing two classes of drugs that do just that. One would stop the body from producing the capsaicin molecule. Another would soak it up, before it reached the receptor on the neuron.

And crucially, these drugs do not seem to have the same potential to become addictive¹⁵, the way narcotics do. Hargreaves says the first class of drugs could begin clinical tests in humans within the next six months.
 

1 painkiller   

n.止痛药

参考例句：

• I shall persuade him to take the painkiller.我将说服他把药吃下去。
• The painkiller only provides him a short respite from his pain.止痛药仅仅让他在疼痛中有短暂的疏解。

2 chili   

n.辣椒

参考例句：

• He helped himself to another two small spoonfuls of chili oil.他自己下手又加了两小勺辣椒油。
• It has chocolate,chili,and other spices.有巧克力粉，辣椒，和其他的调味品。

3 investigation   

n.调查，调查研究

参考例句：

• In an investigation,a new fact became known, which told against him.在调查中新发现了一件对他不利的事实。
• He drew the conclusion by building on his own investigation.他根据自己的调查研究作出结论。

4 narcotics   

n.麻醉药( narcotic的名词复数 )；毒品；毒

参考例句：

• The use of narcotics by teenagers is a problem in many countries. 青少年服用麻醉药在许多国家中都是一个问题。 来自《现代汉英综合大词典》
• Police shook down the club, looking for narcotics. 警方彻底搜查了这个俱乐部，寻找麻醉品。 来自《简明英汉词典》

5 activate   

vt.使活动起来，使开始起作用

参考例句：

• We must activate the youth to study.我们要激励青年去学习。
• These push buttons can activate the elevator.这些按钮能启动电梯。

6 activated   

adj. 激活的 动词activate的过去式和过去分词

参考例句：

• The canister is filled with activated charcoal.蒸气回收罐中充满了活性炭。

7 activating   

活动的，活性的

参考例句：

• "I didn't say we'd got to stop activating the masses! “我并没说就此不发动！ 来自子夜部分
• Presumably both the very small size and activating influence of fluorine atoms contribute to this exception. 这大概是由于氟原子半径小和活性高这两个原因的影响，氟原子对这种例外做出了贡献。

8 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

9 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

10 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

11 isolated   

adj.与世隔绝的

参考例句：

• His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
• Patients with the disease should be isolated. 这种病的患者应予以隔离。

12 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

13 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

14 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

15 addictive   

adj.(吸毒等)使成瘾的，成为习惯的

参考例句：

• The problem with video game is that they're addictive.电子游戏机的问题在于它们会使人上瘾。
• Cigarettes are highly addictive.香烟很容易使人上瘾。