A simple connective tissue called interstitium that lies beneath the skin surface and surrounds organs was now found to possess the characteristics of an organ. Researchers made the discovery when they are experimenting with a new type of endoscope that uses laser and fluorescent dyes to identify the living tissue in patients. They found that the bile duct contained cavities which do not fit its anatomy. Fascinated by the finding the researchers took the results to a pathologist Neil Theise. Together, they devised a novel method to extract bile duct biopsies by freezing the tissue. The traditional method involves dehydration of the sample followed by the chemical fixation to the slides. So, this preserved the anatomical structure close to the living tissue.
The close observation of the tissue revealed that it is an interconnected network of fluid-filled cavities supported by a meshwork of collagen and elastin fibres. Since traditional method involves some sort of cellular degradation these spaces were never identified and were thought of as an artefact of processing. But it was now found that they are not artefacts and in fact, they are the remnants of the collapsed spaces. The series of space supported by meshwork are thought to act as shock absorbers for the organs during the daily function.
The interstitium acts as a sort of pre-lymph and drains liquid in body’s lymphatic system and critical to the function of immune cells. So interstitium can act as a source of cancer metastasis when it invades it. However, not everyone is in agreement to consider interstitium as an organ. Some scientists such as Michael Nathanson from the Yale University of Medicine opined that it may be analogous to blood vessels. These are present in every organ but cannot be considered as an organ themselves. However, a lot of research has to be done to know its function as well as impacts on the body. Whatever may be the case, this new research just reminds us of the complex architecture of the human body and there is much more to learn. If interstitium has been declared as an organ it would be the 80th organ to be classified in the human body.
The Research findings have been published in the journal Scientific Reports.