Thursday, 10 February 2011

Who is your Valentine; Cupid or a fish?

Some creatures have almost magical abilities to recover from trauma. For example starfish can regenerate their legs, and worms can survive being cut in two, although only the part with the heart! However, these feats pale when compared to the zebra fish, which can fix a broken heart. These common little black and white striped fish have nothing to do with soothing jilted lovers, but amazingly zebra fish can regenerate heart tissue. They also have the ability to regenerate fins and eye parts.

Harvard scientists surgically removed 20% of the heart tissue of ten adult zebra fish, then put them back in the water to see what would happen. At first the fish swam weakly near the bottom of the tank; a microscope revealed that in the early stages of recovery, scar tissue partially clotted the wounded organ.

However, after about ten days the fish were back to their normal routines, swimming vigorously. Of the ten fish with broken hearts, eight fully recovered. Another microscope inspection revealed that the recovered fish had regenerated their heart tissue with virtually no scarring.

How, exactly, zebra fish mend their broken hearts is of great interest to scientists. When people recover from a heart attack their hearts are never quite the same. A healing heart normally accumulates scar tissue instead of muscle growth. The scarred, weakened heart cannot contract and pump blood as efficiently as an undamaged heart.

Since zebra fish and humans share many of the genes responsible for cell regeneration, further study may lead to techniques for scar-free human heart repair.

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