There are "Eyes" on the Skin

Human melanocyte skin cells send out signals, using calcium, when exposed to ultraviolet light, a key step in producing the protective pigment melanin. Researchers have found that melanocytes use a light-sensitive receptor, called rhodopsin, also found in the retinas of our eyes, to detect certain wavelengths of ultraviolet light. (Picture from: http://www.livescience.com/)

For the layman, the skin turned black from the sun is a process that is easy to understand. A study demonstrated that the skin can detect UV radiation type A (wavelength 320-400 nanometers) using light-sensitive receptors which was originally considered to exist only in the eye. Once detected, the skin begins to produce melanin in a few hours.

The ability of the skin such as the eye could detect light triggers the production of melanin proved much faster than originally predicted. Previously, researchers only know the production of melanin occurs several days after UV-B radiation (wavelength 315-280 nm) begins to damage the DNA.

"Once you start on sun-exposed skin immediately knew they were exposed to UV radiation," said Elena Oancea, professor of biology at Brown University. "This process is very fast, much faster than what was previously known."

Researchers believe the melanin protects the DNA in skin cells against damage from UV-B rays by absorbing the radiation coming. This process is not perfect, that is why people should use sun block cream. But a recent study in the journal Current Biology shows that the body much more quickly alerted defense, even before the blackened skin.

In experiments using a melanin-producing skin cells in the laboratory, Oancea and colleagues, Nadine Wicks, found that the cells that contain rhodopsin, the photosensitive receptors are used to detect light eyes.

When UV-A light receptor rhodopsin mashing, calcium signaling is triggered in a few seconds. After one hour, melanin accumulates. Although these findings reveal the mechanism of skin protection against radiation, Oancea stating it was not a reason for someone to leave the habit of protecting the skin from the sun. *** [SCIENCEDAILY | BROWN UNIVERSITY | KORAN TEMPO 3700]