Flashcards in Ultraviolet Damage and Repair Deck (14):
Which type of UV light is responsible for most of the negative physiological effects?
UVB, although UVA can also cause DNA damage
UVA is ______ than UVB.
longer (it can thus penetrate deeper into the skin and affect fibroblasts and connective tissue)
Why don't we worry about UVC and solar light with shorter wavelengths than UVB?
Because the middle and upper atmosphere scatter it
_____ light induces vitamin D synthesis.
List the five main categories of UVR's effects on skin.
(1) vitamin D synthesis; (2) damage to DNA, RNA, proteins, and lipids; (3) apoptosis; (4) pro-inflammatory effects; and (5) induction of innate defenses
_____ is the most effective UV light at inducing ROS generation and immunosuppression.
UVB acts primarily on _________.
Langerhans cells, keratinocytes, and melanocytes
What is the precursor molecule in vitamin D synthesis?
Other than thymine dimerization, what does UVR do to DNA?
Pyrimidine 6,4 pyrimidone formation (UVB), and hydroxyguanosine formation (UVA and singlet oxygen)
By what two mechanisms does UVR induce immunosuppression?
(1) stimulating the immune-regulatory molecules, such as IL10; and (2) decrease in Langerhans proliferation
What pro-inflammatory molecules are released by UVR?
IL-1, TNF-alph, prostaglandins, leukotrienes, and histamine
List four ways that the skin can protect itself against UV damage.
DNA repair, apoptosis of excessively damaged cells, ROS defense, and melanin
Where are melanocytes located?