运动休闲－最新研究成果：“伟哥”能治心脏病

The sex drug Viagra appears to cut the effects of stress on the heart by 50 percent, according to a report by researchers at Johns Hopkins University.The report shows that the drug, which is normally used to treat impotence, blunts the strengthened heartbeat caused by chemically induced stress.

Earlier research by Dr. David Kass, lead author of the study, found that Viagra blocked the short-term effects of hormonal¹ stress in the hearts of mice and also prevented the long-term cardiac effects of chronic² high blood pressure in mice.

In the current study, 35 healthy men and women with no signs of heart disease received two separate injections of dobutamine over three hours. Dobutamine increases heart rate and pumping strength.

Between injections, the patients were given Viagra or a placebo³. Then they all were given a second dobutamine injection. After the first injection of dobutamine, the force of heart contraction⁴ increased 150 percent in all the patients. However, in the group treated with Viagra, the increased heartbeat was slowed by 50 percent.

"Viagra puts a brake on the effect of dobutamine," Kass said. "It reduces the stimulation⁵ of the heart so that the contraction of the heart was less strong." He said the research sets the stage for more specific studies of its use to treat heart problems

However, Kass added that the study also shows that Viagra helps control heart function only when the heart is under stress, and has little impact under normal conditions.

重点词注释

Viagra: sex drug, normally used to treat impotence
Dobutamine: can increase heart rate and pumping strength
placebo: injection with no medical function

1 hormonal   

adj.激素的

参考例句：

• Some viral diseases are more severe during pregnancy, probably tecause of hormonal changes. 有些病毒病在妊娠期间比较严重，可能是由于激素变化引起的。
• She underwent surgical intervention and a subsequent short period of hormonal therapy. 他接受外科手术及随后短暂荷尔蒙治疗。

2 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。

3 placebo   

n.安慰剂；宽慰话

参考例句：

• The placebo has been found to work with a lot of different cases.人们已发现安慰剂能在很多不同的病例中发挥作用。
• The placebo effect refers to all the observable behaviors caused by placebo.安慰剂效应是指由安慰剂所引起的可观察的行为。

4 contraction   

n.缩略词，缩写式，害病

参考例句：

• The contraction of this muscle raises the lower arm.肌肉的收缩使前臂抬起。
• The forces of expansion are balanced by forces of contraction.扩张力和收缩力相互平衡。

5 stimulation   

n.刺激，激励，鼓舞

参考例句：

• The playgroup provides plenty of stimulation for the children.幼儿游戏组给孩子很多启发。
• You don't get any intellectual stimulation in this job.你不能从这份工作中获得任何智力启发。