How is it that pharmaceutical companies can develop drugs for humans that lower their blood pressure? Drugs like Lipitor, Levacor, Zocor, and other blood pressure reducing drugs were all tested first on animals. After any drug is developed the next step is to determine both its kinetic and dynamic effects on an organism. You may already know that rats are consistently used in research labs, this is because they are an excellent model organism. That is their DNA differs from humans only slightly and many of our proteins are the same.
So we have our new blood pressure reducing drug, but how to test it on our rats? There are a few methods we can use to measure a rats blood pressure changes. A tail cuff will enclose the tail of the rat while it is still awake and restrict blood flow just like the cuff a nurse would use to measure our own blood pressure. This method is a bit inaccurate because a rat doesn’t take to kindly to having its tail squeezed.
Another method is to use a catheter inserted directly into the blood vessel and then use a blood pressure transducer to measure the changes. This method is highly accurate, but comes at a few more risks. The catheterization requires a surgery and risks infection of the animal, especially if their immune system is compromised. Additionally the catheter line can be compromised by blood clots or the animal somehow damaging it. However, the catheter is an still an excellent research tool because the accuracy of the measurements outweighs the risks in many cases.