Scientists have stumbled upon a new “organ” just beneath the skin. They have named it the “interstitium layer”. It contains collagen and elastin, proteins that give the skin its durability and elasticity, and is found in spaces filled with interstitial fluid, and lines tissues that suffer physical strain.
Investigations have revealed that the layer is found in tissues lining the gut, lungs, blood vessels, and muscles. The layer was not discovered until now as the usual methods of investigation (wherein samples are sliced and dyed before observing under a microscope) drained the fluid, giving the sample the appearance of one continuous layer of dense collagen. This time, researchers at New York University School of Medicine and NYU Langone Health Center used a regular endoscope that looked at tissues illuminated with laser, a technique called probe-based confocal laser endomicroscopy. They also used a living tissue instead of slicing the samples.
The tissues were seen in areas that suffered force, suggesting that the fluid-filled spaces may act like shock-absorbers. It was also noticed that the fluid drains into the lymphatic system, which is spread throughout the body.
Researchers say that the interstitium layer could help understand how cancer spreads in the body, and prove to be a potential diagnostic tool. It is the cells in this layer that age and contribute to skin wrinkles, the progression of certain diseases, and stiffening of limbs. However, not all are convinced of calling the layer an “organ”, more research is being carried out.