PMID- 11601655
OWN - NLM
STAT- MEDLINE
DCOM- 20020418
LR  - 20191025
IS  - 0893-5785 (Print)
IS  - 0893-5785 (Linking)
VI  - 14
IP  - 5
DP  - 2001 Oct
TI  - Variation in melanin content and composition in type V and VI photoexposed and 
      photoprotected human skin: the dominant role of DHI.
PG  - 337-47
AB  - A combination of techniques, including high-performance liquid chromatography 
      (HPLC), spectrophotometric measurements, and a novel method for quantifying 
      melanosome morphology, were applied to the analysis of melanin content and 
      composition in highly pigmented (Fitzpatrick type V and VI) human skin. We found 
      that total epidermal melanin content is significantly elevated in photoexposed 
      type V and VI skin (approximately 1.6 x), while analysis of individual melanin 
      components suggests that pheomelanin content increases only slightly, whereas 
      5,6-dihydroxyindole-2-carboxylic acid (DHICA)-eumelanin and to a greater extent 
      5,6-dihydroxyindole (DHI)-eumelanin content are both markedly elevated. Analysis 
      of the relative composition of epidermal melanin in these subjects revealed that 
      DHI-eumelanin is the largest single component (approximately 60-70%), followed by 
      DHICA-eumelanin (25-35%), with pheomelanin being a relatively minor component 
      (2-8%). Moreover, there was a comparative enrichment of DHI-eumelanin at 
      photoexposed sites, with a corresponding decline in the relative contributions 
      from DHICA-eumelanin and pheomelanin. There was also a good correlation and close 
      agreement between the concentration of spheroidal melanosomes determined by 
      morphological image analysis and the concentration of pheomelanin determined by a 
      combination of HPLC and spectrophotometric analysis (r = 0.89, P < 0.02). This 
      study demonstrates the usefulness of melanosome morphology analysis as a 
      sensitive new method for the quantification of melanin composition in human skin. 
      The data also suggest that DHI-eumelanin formation is the dominant pathway for 
      melanin synthesis in heavily pigmented (Fitzpatrick V and VI) skin types in vivo, 
      and is the favoured pathway when melanin production is increased in chronically 
      photoexposed skin.
FAU - Alaluf, S
AU  - Alaluf S
AD  - Unilever Research, Colworth Laboratory, Sharnbrook, Bedford, United Kingdom. 
      simon.alaluf@unilever.com
FAU - Heath, A
AU  - Heath A
FAU - Carter, N
AU  - Carter N
FAU - Atkins, D
AU  - Atkins D
FAU - Mahalingam, H
AU  - Mahalingam H
FAU - Barrett, K
AU  - Barrett K
FAU - Kolb, R
AU  - Kolb R
FAU - Smit, N
AU  - Smit N
LA  - eng
PT  - Journal Article
PL  - Denmark
TA  - Pigment Cell Res
JT  - Pigment cell research
JID - 8800247
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Indoles)
RN  - 0 (Melanins)
RN  - 4790-08-3 (5,6-dihydroxy-2-indolylcarboxylic acid)
RN  - Z3OC8499KG (5,6-dihydroxyindole)
SB  - IM
MH  - Biopsy
MH  - Chromatography, High Pressure Liquid/methods
MH  - Enzyme Inhibitors/metabolism
MH  - Epidermal Cells
MH  - Epidermis/*chemistry/radiation effects
MH  - Humans
MH  - Indoles/*metabolism
MH  - Light
MH  - Melanins/chemistry/*metabolism
MH  - Melanosomes/*chemistry/*ultrastructure
MH  - Molecular Structure
MH  - Skin Pigmentation/*physiology
MH  - Statistics as Topic
EDAT- 2001/10/17 10:00
MHDA- 2002/04/19 10:01
CRDT- 2001/10/17 10:00
PHST- 2001/10/17 10:00 [pubmed]
PHST- 2002/04/19 10:01 [medline]
PHST- 2001/10/17 10:00 [entrez]
AID - 10.1034/j.1600-0749.2001.140505.x [doi]
PST - ppublish
SO  - Pigment Cell Res. 2001 Oct;14(5):337-47. doi: 10.1034/j.1600-0749.2001.140505.x.