Viagra, used to treat impotence in men, has been found to reduce the harmful effects of stress on the heart, scientists said yesterday.

　　The drug was originally designed as a candidate treatment for heart disease before its effect on genital blood vessels was appreciated.

　　Now researchers at the Johns Hopkins University School of Medicine in Baltimore have measured the strength of heart beats in a group of 35 adult volunteer patients in whom stress was induced with the drug dobutamine. This chemical mimics the effects of emotional or physical stress by increasing the force of heartbeats and boosting the flow of blood in the body, which can lead to permanently raised blood pressure.

　　The men and women were randomly assigned to two groups, either to be treated with Viagra or a placebo. In those given Viagra, the strength of the heart's contractions was reduced by half, from 150 per cent to 75 per cent.

　　Writing in the journal Circulation, Prof David Kass, who led the study, says: "Sildenafil [Viagra] effectively puts a 'brake' on chemical stimulation of the heart. Knowing more about the effects of sildenafil on heart function will allow for safer evaluation of its use as a treatment for heart problems."

　　Dr Charmaine Griffiths, of the British Heart Foundation, said: "Viagra has been a real advance in treating impotence.

　　"The findings that Viagra affects blood pressure are not surprising - before it was known as a successful treatment for impotence, it was actually being researched for lowering effects on blood pressure.

　　"However, if you have a heart condition you should check with your doctor before taking Viagra.

　　"Mixing this drug with other heart medicines or taking it if you have angina [heart pain on exercise] without advice from a health professional or GP can be dangerous for heart patients," she said.

美国研究人员发现伟哥能帮助减轻心脏压力

　　伟哥是一种治疗男性阳痿的药物，而美国研究人员最近又发现了这种药物的新功能——减轻压力对心脏的有害影响。

　　据英国《每日电讯报》10月25日报道，其实，在被认为对男性生殖器血管起作用之前，伟哥最初就已被当成是一种心脏疾病的候选治疗药物。

　　美国马里兰州巴尔的摩约翰·霍普金斯大学医学院的研究人员通过实验发现，伟哥确实能够减轻压力对心脏的损害。

　　研究过程中， 35名成年志愿者经受药物多巴酚丁胺(dobutamine)引起的压力，而工作人员则测量出他们的心跳力度。多巴酚丁胺这种化学药品通过增加心跳力度以及加速血液在身体中的循环来模拟情绪或身体压力带来的效果。

　　然后，在实验过程中，男性志愿者和女性志愿者被随意分在2个组中，研究人员通过伟哥或安慰剂对他们进行治疗。在那些用伟哥进行治疗的人当中，他们心脏的收缩力减少了一半，从150%降低至75%。

　　对此，这项研究的负责人大卫·凯斯教授表示，伟哥能够有效地减少化学药品对心脏的刺激；更多地了解这方面(伟哥对心脏功能的影响)的信息，将让人们对把伟哥作为一种治疗心脏问题的药物做出更为可靠的评价。英国心脏基金会的查尔迈恩·格里费思医生也表示：“在治疗男性阳痿方面，伟哥曾是一个真正的进步。其实，伟哥会对血压有影响这个发现一点也不令人感到惊讶——因为在伟哥被众人所熟知是治疗阳痿的有效药物之前，科学家就曾对其进行过降低对血压影响的研究。”

　　尽管如此，专家还同时指出，如果你的心脏出现了问题，那么在服用伟哥这种药物之前，最好先向医生进行咨询。

　　报道说，这一研究成果被发表在新一期美国《循环》杂志上。(

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