According to researchers, tanning is not just a superficial reaction. The exact reaction between the skin and the radiation from the sun still largely remains a mystery. The reactions that go on in the skin are more complex. It has come to light that detection of UV radiation by the skin takes place through a receptor. Previous researches have shown that this receptor is present in the retina of the eye. The production of melanin takes place in less than two hours. This receptor is light sensitive and is activated when exposed to light. Previous researchers suggested that the production of melanin took place much after the DNA of the body had been damaged by UB radiation. This research presents contradictions to facts that were already known. As per the research, the skin begins its preparation for exposure to sunlight prior to exposure to sun.
The lead author of the study, Elena Oancea who is an assistant professor of biology at Brown’s University Department of Molecular Pharmacology and Biotechnology said that the reaction of skin to UV rays is very fast and not slow like what previous researches suggested. She said that the brain sent out signals to the skin as soon as it was exposed to the sun. Melanin is the pigment responsible for protection of DNA of skin against UV rays. It absorbs radiation, thus not allowing sunlight from affecting the DNA. However, as per latest research, the defense mechanism of the body kicks into high gear much before tan appears. Researchers also suggest that although the defense mechanism of the body is effective in providing protection against radiation from sun, the mechanism is not foolproof and use of sun blocks is still recommended.
Human eye contains a photosensitive receptor called rhodopsin. These detect sunlight and trigger calcium ions that in turn trigger melanocytes, which are the melanin producing cells in the skin. The present study traced the route by which this entire process occurs. The research was conducted in different stages. The first aim was to evaluate whether calcium ions were in activated by sunlight. The researchers also included a skin factor based on the supposition that skin might also have a light receptor similar to the eye. Then experiments were conducted in this regard, the results were very positive and the amount of calcium released was massive. It is however, unclear whether rhodopsin acts alone or in conjunction with some other kind of receptor.