ÜDS-Sağlık 2011-1 Soru=53

The most important news given in the passage is that —.

The revelation that H2S is produced in the cardiovascular system and helps to control blood pressure caught the attention of many researchers who had been looking for novel ways to protect the heart against damage from oxygen deprivation, as occurs when a clot prevents blood from bringing oxygen to the heart, leading to the death of cardiac tissue. In 2006, Gary Baxter reported that in isolated rat hearts, which were first provided with saline solution to mimic blood supply and then deprived of the saline to mimic a heart attack, administering H2S to these isolated hearts before halting the saline supply reduced the extent of cardiac muscle damage. Later, David Lefer showed that mice engineered to produce more H2S in the heart were better able to tolerate oxygen deprivation caused by a clot and more resistant to the damage that often ensues when blood flow is restored to tissues after a period of deprivation. Findings such as these suggest that H2S could be used to prevent or treat hypertension, heart attacks and strokes in humans. But the gas's ability to relax blood vessels means that its potential applications could extend to other blood vessel problems too - including erectile dysfunction.