What Is Transplantation?
Have you ever moved from one place to another? Perhaps from one city or state to another, or even to another country? We call people who have moved from one place to another transplants. Transplant means moving something from one place to another and often involves a little bit of hassle.
In science, transplantation refers to the movement of an organ, tissue or general body part from one place to another. If you've ever obtained or renewed a driver's license, the clerk probably asked if you wanted to be an organ donor. If you said 'yes', when you die, your organs may be harvested and transplanted to another person. This type of transplantation is known as allotransplantation.
What Is Allotransplantation?
Allotransplantation is the movement of an organ, tissue or other body part from one person to another. Just like an in-state or in-country move, the organ or tissue being transferred stays within the same species. And you don't always have to be dead before your organs or tissues can be transplanted. For example, in kidney transplants, a living person can donate one of his or her kidneys to another person because most of us can survive with just one of these organs.
Allotransplantation
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While allotransplantations must occur within the same species, that species doesn't necessarily have to be human. For instance, if your puppy needs a new kidney and a donor dog is available, then your puppy will get a new kidney through allotransplantation.
Just as transplanted persons often have to get used to new state laws, organs and tissues that move from one person to another have to get used to a new body. In general, new bodies prefer their original parts and often fight off new organs and tissues in a process called rejection. This is why medication is often required for transplant patients.
Allografts and Xenografts
The new kidney your puppy received in the allotransplantation is called a allograft or homograft. A graft refers to the piece that is removed from the donor and given to the recipient.
Allograft
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Xenografts (pronounced zee-no-grafts or zen-oh-grafts) on the other hand, cross species. A xenograft refers to an organ or tissue from a donor belonging to a different species from the recipient. We call this transfer of organs and tissues between members of different species xenotransplantation.
For example, what happens if a patient needs a new heart? How about a non-human donor? Believe it or not, this has been done before. During the 1980's, doctors transplanted the heart of a baboon heart into a human infant in an attempt to save her life. 'Baby Fae' survived for just 20 days after the controversial operation. The cause of death was organ rejection.
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As you can imagine, if a recipient body doesn't like new organs or tissues from its own species, it definitely won't like donations from a different species. Nevertheless, scientists have already tested the transfer of parts of a pig pancreas to monkeys with diabetes. So far, their efforts have been met with some success. In the future, clinical trials will help determine if xenografts involving pig pancreases can help humans with diabetes.
Lesson Summary
Transplantation is the movement of organs, tissues or other basic body parts from one place to another. Allotransplantation refers to the transplant of an organ or tissue from one organism to another within the same species, such as from human to human or dog to dog. We call this donated organ or tissue a allograft or homograft. By comparison, a donated organ or tissue from a donor to a recipient of a different species is called a xenograft.
A xenotransplantation is the transplant of an organ or tissue from one species to a different species. Both allotransplantations and xenotransplantations may be complicated by rejection of the donor organ or tissue by the recipient's body, which requires medication.