Tarantula's venom used to develop heart drug

The venom of the tarantula spider is being used to develop a revolutionary drug to combat heart flutter, one of Britain's commonest cardiac disorders.

The venom of the tarantula spider is being used to develop a revolutionary drug to combat heart flutter, one of Britain's commonest cardiac disorders.

Scientists have discovered that a small protein, or peptide, isolated from the venom of Grammostola spatulata - a hairy tarantula that can grow to the size of a man's hand - can significantly inhibit cardiac arrhythmia, when heart muscle goes into uncontrolled spasms.

The researchers, led by Frederick Sachs of the State University of New York in Buffalo, believe that the peptide, called GsMtx-4, could become the first drug developed that is specifically directed against arrhythmic disorders of the two atria, the smaller pair of the heart's four chambers.

"Our findings open a window on cardiac arrhythmogenesis and point the way towards developing a new class of drugs," the scientists say in a study published in the journal Nature.

The tarantula peptide works by blocking the microscopic channels in the muscle cells of the atria. When stretched, these channels trigger a muscle contraction. Atrial fibrillation occurs more often as people age. It is considered a risk because the fluttering can generate blood clots which can move to the brain and cause a stroke, said Denis Noble, professor of cardiovascular physiology at Oxford University.

"This research by the Sachs group is important. I don't think there is any doubt about that." He said few treatments existed for the condition so the findings could prove invaluable to an ageing population.