DEFINITION of 'Commercial'. Relating to commerce. In the investment field, the term commercial is generally used to refer to a trading entity engaged in business activities that are hedged by positions in the futures or options markets.
The melanocortin 1 receptor controls which type of melanin is produced by melanocytes. When the receptor is activated, it triggers a series of chemical reactions inside melanocytes that stimulate these cells to make eumelanin. If the receptor is not activated or is blocked, melanocytes make pheomelanin instead of eumelanin.
We all have pigment-producing cells in our skin called melanocytes. These melanocytes produce melanin pigment and feed it to keratinocytes, the normal skin cells that form the outer barrier of our skin.This barrier protects us from the insults of nature, and importantly, from the sun.This pigment prevents us from being damaged by the sunâs powerful rays.hese melanocytes produce melanin pigment and feed it to keratinocytes, the normal skin cells that form the outer barrier of our skin.This barrier protects us from the insults of nature, and importantly, from the sun. This pigment prevents us from being damaged by the sunâs powerful rays.