| what I read about these chemicals and what I know about mutagens is this: it alters the base pair sequence of a DNA strand. It changes the codons and the instructions that those codons carry. Whatever protein was supposed to be made, probably won't be after mutation.... although there are 60 codon possibilities and only 20 amino acids, so there is some redundancy built into the system... whatever was supposed to happen, probably won't because the proper protein (made up of amino acids) isn't being created.
After bifunctional photoadducts are formed in keratinocyte and melanocyte DNA, increased mitosis of basal layer keratinocytes and melanocytes is observed. In fact, the melanocyte population will double or triple within 3-7 days. Melanocyte hypertrophy and increased arborization is also seen.
What this is saying, as I read it, is that that altered DNA (caused by psoralens) now directs cells (keratinocytes and melanocytes) to divide, divide, divide, divide, divide repeatedly. This must cause the darker tan.... due to more of these cells being produced.
It is the same mechanism as a cancerous tumor-- excessive cell division. As I said before, anytime you mess with DNA, you are playing a risky game. I am interested to know if these "intentional" DNA mutations always occur in the same way without harmful side-effects...
do they just cause hyperpigmentation of cells? are the signs just a warning that people might get too dark? or are there other risks involved?
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