Scientists at the University School of Medicine in New York (USA) have found a new organ in the human body. It is the so-called interstice. It is a network of fluid-filled connecting tissues that are located under the skin and that cover many other organs. Until now it had gone unnoticed because the techniques of anatomical observation, which focus on fixing tissue samples with chemicals, did not allow observing it. In general, there was talk of an interstitial space, located between the cells, but not of an organ itself.

This discovery has the potential to lead to dramatic advances in medicine, including the possibility that taking samples of interstitial fluid becomes a powerful diagnostic tool, Neil Theise, a physician and researcher at the University School of Medicine, explains in a statement. of New York and co-author of the study.

According to an article published in Scientific Reports by this and other authors, the interstitium has a great importance for the functioning of all the organs and the behavior of most of the important diseases. Among these, cancer stands out, because sometimes it can spread through this network.

One of the largest organs of the body

The interstitium is located under the skin and covers at least the digestive system, the excretory system, the lungs, the arteries, the veins and the cell bundles of muscle fibers. In this way, they are all interconnected by a system of liquid compartments.

The interstitium turns out to be one of the largest organs of the human body, next to the skin. It is composed of a structure of collagen and elastin, two proteins that give strength and elasticity, respectively. Both form a "scaffold" that is filled with fluid, and the result is that the organ functions as a buffer for the movements of the viscera, muscles and blood vessels, which occur as a result of the pumping of the blood or the natural movement of the body. body.

In addition, the cells that make up the interstitium produce a portion of the fluid that feeds the lymphatic system, a part of the circulatory system that is responsible for transporting the lymph, and which is essential to drain body fluids, the functioning of the immune system in general and the response of inflammation in particular.

Wrinkles and aging

As happens in the rest of the body, aging deteriorates the interstitium. When that happens, researchers have explained that it loses the ability to produce collagen and elastin and that this contributes to skin wrinkling, limbs become stiff and certain diseases advance.

Until now, anatomy counted on the existence of interstitial fluid, a portion of fluid located between cells, but not with an interstitial organ in itself. Apart from this fluid, the other sources of fluids of the body are inside the cells, in the circulatory system (heart, veins, arteries, capillaries, etc.) and in the lymphatic vessels.

Why had it not met so far?

If you had never found any indication of the interstitium, it is because the traditional way of observing the tissues of the organism destroyed its structure. These techniques consist in making small cuts of tissues and fix them with chemical products to prevent deterioration and facilitate their observation in optical and electronic microscopes. The problem is that by doing this, the tissues lose their original appearance. In the case of the instersticio, this has always caused that what in vivo can remember a sponge or a Swiss cheese, in the microscope it is collapsed and pressed.

On this occasion, a new technology has been able to observe the interstice as it really is. For this purpose, a technology known as confocal laser endomicroscopy has been used, basically consisting of an endoscopy in which, instead of a camera, a laser and sensors detect fluorescent signals that bounce off the tissues.

In this study, the researchers took samples of bile ducts just before operations of cancer patients. After observing the presence of the interstitium on the pancreas and the bile ducts, they began to recognize it in other points of the organism, where the organs move or are compressed by forces.

Source: ABC