醫(yī)學考博英語聽力練習素材（四）

The ingredient that makes hot chilies hot is called capsaicin—it can set your mouth on fire. But the spicy compound has a soothing effect too: in your gut, it kicks off a chemical cascade that might calm the immune system reduce inflammation.

Researchers studied that phenomenon in mice. Once inside the gut, the capsaicin molecules plugged into a specific receptor, spurring the release of another compound, called anandamide.

Anandamide happens to be an endocannabinoid—similar to active ingredients in marijuana—which binds to cannabinoid receptors in the gut. That last step in the cascade ramped up the production of cells that damp down inflammation in the mice—even cured them of a mouse model of diabetes type 1, an autoimmune disease.

If all this sounds a bit similar to the chemical messaging that happens in the brain...that's because it is. "The gut has a very large nervous system. It's almost as large as the brain itself." Pramod Srivastava, an immunologist at UConn Health one of the study's leaders.

"We don't quite fully understwhat this huge amount of neurons are doing in the gut. We don't understits language, the molecules mediators. I think with this work we can at least claim to have found a couple of words in that language." The study is in the Proceedings of the National Academy of Sciences.

So to recap that chemical chain: chilies cause the production of endocannabinoids, which produce immune suppressant cells, which soothe inflammation. So, what if you cut out the chili initiator, just eat cannabinoids—pot brownies, stuff like that?

"Obviously we are very interested in people who use edible cannabinoids. I'm extremely curious if people with colitis or Crohn's disease, who are edible pot users, do they benefit from it? I have no idea. But it's something we can now find out because sizable numbers of people are consuming those edibles.”

讓辣椒產生辣味的成分叫做辣椒素，它會讓你的嘴巴冒火。不過這種辛辣的化合物也有舒緩作用：它會在腸道中觸發(fā)一種化學級聯(lián)反應，這種反應可以穩(wěn)定免疫系統(tǒng)并減少炎癥。

研究人員在小白鼠身上對這一現(xiàn)象進行了研究。一旦進入腸道，辣椒素分子便會進入一種特殊的受體，促進另一種名為 “大麻素” 的化合物的釋放。

這是一種內源性大麻素，類似于大麻中的有效成分，它會與腸道中的大麻素受體結合。級聯(lián)反應的最后一步使小白鼠體內抑制炎癥的細胞數(shù)量增加，甚至治愈了患有 1 型糖尿病的小白鼠，1 型糖尿病是一種自體免疫性疾病。

這些聽起來可能有點像大腦中的化學消息傳遞，那是因為就是這樣?！澳c道擁有一個非常龐大的神經系統(tǒng)。幾乎和大腦的神經系統(tǒng)一樣龐大?！逼绽隆に估锿咚顾呤强的腋翊髮W健康中心的免疫學家，也是這項研究的負責人之一。

“我們不完全了解腸道中的大量神經細胞有何作用。我們不懂神經細胞語言，也不了解這些分子和介質。不過我認為，至少我們通過這項研究發(fā)現(xiàn)了這種語言的幾個單詞?！?這項研究發(fā)表在《美國科學院院刊》上。

現(xiàn)在來回顧一下這個化學反應鏈：辣椒催生內源性大麻素，內源性大麻素產生免疫抑制細胞，這種細胞緩解炎癥。那么，如果去掉辣椒這個引發(fā)劑，直接獲取大麻素，比如吃大麻布朗尼之類的東西，會怎樣呢?

“顯然，我們對攝取可食用大麻素的人非常感興趣。我非常好奇的是，如果患有結腸炎或克羅恩病的人食用大麻，能緩解病癥嗎?我并不知道答案。不過因為現(xiàn)在有相當多的人在服用可食用大麻，所以我們可以找到答案。”