Over the years, we have begun to hear more and more about putting tiny robots, the size of a blood cell into human bodies. The purpose of these devices would be to repair our bodies, if anything goes wrong. We have also heard and read articles over this period of time that suggest, that a human might have more capabilities than he realized. Is it possible that the answer to our longevity and good health has been out there all along, but mabye we weren't sufficiently aware of it? It just might turn out that the answer to this question will be yes. It is too early to tell yet, but now that we are unlocking genes and such, we have a good chance to find it. I say that the answer is out there, because there are animals that can regenerate body parts when one is lost, but even more importantly they can repair things like their heart if it gets damaged. An example of this would be the lowly newt. If we can find out the mechanics of how the newt does this, we might be able to apply the results to humans. Can you imagine what this would do for our soldiers? If one loses an arm, leg or foot, he might be able to simply regrow one with the right stimulation.

Of all the different newt species, one of the favorites, for the scientists to work with, is the Red Spotted Newt, known as Notophthalmus viridescens. It lives here in our own backyard. If look at this newt's ability to repair its own heart and compare it to our own ability for recovery, we notice that the newt can repair its heart as good as new, while we humans become full of scar tissue. Possibly, we will be able to change that sequence of repair so that instead of the scar tissue, we will get a true repair that will make our hearts as good as new. So what do we know of this process today? The newt's heart muscles will change when its heart is damaged. They can differentiate. Many of the problems associated with heart muscles were reduced dramatically when the newt's heart was being repaired. The next thing that we know about this process, is that there is a massive cell division to rebuild the heart. Another thing that we have found out, is that there is a protein that helps the newts with the heart rebuilding process called Phospho-H3. This is the key, it stops scar tissue and allows the building process to go on unimpeded. The researchers wanted to know if stem cells were employed for this repair, but to their surprise, none were found.

When we talk of regenerating body parts, surprisingly that works a different way, even in the same animal, which makes this power even more remarkable. When the newt has to develop cells to build a new tale, for example, a signal is sent to the body and blastema cells are created, they are a lot like stem cells. No one knows yet where this signal comes from. Scientists have a suspicion though, they think that the signal comes from the part of the body that harbors the wound. One of the commonalities that blastema cells have with stem cells is the ability to change into other cell types. One test that the scientists used to see if there was actually some type of signal sent to tell the cells what to do was to inject cells into the area where the limb had been lost. The cells changed immediately and added to the repair effort. Next the scientists injected the same cells into a good limb and nothing happened. No signal was sent to alter the cells.

Hydra
Photo Source: Offwell Woodland And Wildlife Trust

In February 2007, a human finger was regrown. Oh it wasn't a complete finger, just the tip, but it was regrown. How did he do this? He treated the damaged finger with an extract of pig bladder. The extract of pig bladder is going to be used on soldiers to see if they can regrow lost limbs, using it. Wouldn't this be wonderful? laboratory mice have been grown that can heal themselves, so why not humans? The scientists are hoping that if the experiment to regrow a finger is successful, then we will be able to move on to growing larger limbs What many people don't realize is that humans already have the ability to regrow finger tips, but they usually lose this ability at around 2 years old. Even in adults there is the rare case where a fingertip might be regrown. This might indicate that we have the ability to regrow body parts, but for some reason that ability is dormant in most of us. It might just have to be switched on. It does make you wonder what other abilities we have, doesn't it?

The pig bladder extract that enabled new fingertip growth, is the same stuff that is used on horses to grow new ligaments. Doctors want to try and use this stuff on burn victims and are hoping that it will work as well in those cases as it seems to do in the fingertip loss cases. At this point it is not thought that an entire finger can be regrown yet. It is hoped that if a finger is lost, that maybe as much as an inch will be able to be grown back, allowing the person to get some benefit from it. If you have a stub, you can at least use you fingers to pinch around an object.

Beside the newt, the salamander will also regenerated limbs. While mice can't regrow limbs, some can heal wounds without leaving a scar. They seem to begin the process that leads to the regrowth of a limb, but that is as far as it gets. There are quite a few animals that can regenerate body parts. Here are some:
Amphibians
Brittle star arms
Crabs
Flatworms
Glass lizards
Hydra
Salamanders
Skinks
Turbellarians

In passing, I just want to mention the fact that we are taking two different paths on the regeneration study. First, we are trying to use stem cells to grow new body parts and second, we are studying animals that can regenerate body parts to try and figure out how they do this. Will we be successful? It is beginning to look like we just might be able to figure things out, given a few more years and the resources to do it. Stem cells might not even be necessary, but more than likely they will play some role in the process. Let's hope that all this happens sooner than later.