More and more people suffer from high blood pressure, which dramatically increases the risk of dangerous diseases . But it´s possible that giraffes have the answer to the many questions reserachers have come across in their work regarding how to regulate blood pressure.

Most people know the feeling of seeing stars, when getting up too quickly. But imagine how overwhelming it would be if we were 4.5 m tall and had a blood pressure twice as high! That is what 30 researchers from Aarhus University alongside other institutions have been investigating. They spent a month together in South Africa to get to know more about the distinctive features of giraffes´ biology. Working with 15 giraffes, researchers were in particular investigating how it is possible for a giraffe to adjust to the extreme African weather whist maintaining a normal blood pressure: an ability that humans do not posses.

When a giraffe bends its head to the ground, their blood pressure should increase dramatically – in fact, small blood vessels should naturally burst and their eyes should simply fall out of their sockets. Why doesn’t this happen?

THE MAIN QUESTIONS FOR RESEARCHERS:

  1. Human beings with high blood pressure often have problems with their kidneys. The blood pressure of giraffes is twice as high as ours, so why do they not suffer with similar kidney issues?
  2. Human beings with high blood pressure often suffer from leg swellings. How are giraffes able to avoid this, despite standing still for hours in the heat of the savanna?
  3. Human beings with high blood pressure often suffer from an enlarged heart because of the enhanced work load  in their circulation. Why are giraffes not afflicted with this?  
     

In order to measure the blood pressure of a giraffe in different positions, one of the world’s largest operating tables was built. Each table can be tilted and raised, and is 4m long by 2.5m wide. To then be able to measure the blood pressure, pulse and temperature of the giraffe, special wireless equipment was designed to be attached around its neck.


The researchers found that when a giraffe bends their neck downwards in order to drink, the blood pressure by their heart decreases, thereby preventing the pressure near their heads from rising. Furthermore, at the same time the very small blood vessels in the head become narrower in order to prevent them from bursting.
So now next step for the researchers is to find out, how humans can emulate this ability to regulate blood pressure.

For further information:
Emil Brøndum

etb@fi.au.dk