PMID- 9204951
OWN - NLM
STAT- MEDLINE
DCOM- 19970717
LR  - 20231213
IS  - 0022-202X (Print)
IS  - 0022-202X (Linking)
VI  - 109
IP  - 1
DP  - 1997 Jul
TI  - Pteridines in the control of pigmentation.
PG  - 31-5
AB  - The influence of UVB irradiation on the metabolic pathway for the production of 
      L-tyrosine from L-phenylalanine in the human epidermis has been examined in 12 
      healthy volunteers with photo skin types I-VI (Fitzpatrick classification). This 
      metabolic pathway involves the induction of GTP-cyclohydrolase 1 (GTP-CH-1), the 
      rate-limiting enzyme for de novo synthesis of 
      (6R)L-erythro-5,6,7,8-tetrahydrobiopterin (6-BH4). This essential cofactor 
      controls the production of L-tyrosine from L-phenylalanine via phenylalanine 
      hydroxylase (PAH). The de novo synthesis of 6-BH4 depends on the induction of 
      GTP-CH-1, e.g., by tumor necrosis factor-alpha (TNF alpha). Epidermal suction 
      blister tissues were taken before (0 h) and after (24 and 72 h) UVB exposure with 
      a standardized dosage [1 minimal erythema dose (MED)]. In all cases, there was a 
      significant increase in TNF alpha release, GTP-CH-1 activity, total 6-biopterin 
      level, and PAH activity, indicative of enhanced L-tyrosine production. The 
      response of this metabolic cascade over baseline activities was pronounced in 
      fair photo skin types (I-III) compared to dark skin (IV-VI). Taken together, our 
      results suggest that UVB can control the direct supply of L-tyrosine in the 
      epidermis, and this process may represent an important factor in de novo 
      melanogenesis.
FAU - Schallreuter, K U
AU  - Schallreuter KU
AD  - Department of Biomedical Sciences, University of Bradford, U.K.
FAU - Schulz-Douglas, V
AU  - Schulz-Douglas V
FAU - Bunz, A
AU  - Bunz A
FAU - Beazley, W
AU  - Beazley W
FAU - Korner, C
AU  - Korner C
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Invest Dermatol
JT  - The Journal of investigative dermatology
JID - 0426720
RN  - 0 (Pteridines)
RN  - 0 (Tumor Necrosis Factor-alpha)
RN  - 136459-42-2 (2-amino-4-hydroxy-7-(dihydroxypropyl)-5,6,7,8-tetrahydrobiopterin)
RN  - 0 (Biopterins)
RN  - EC 1.14.16.1 (Phenylalanine Hydroxylase)
RN  - EC 3.5.4.16 (GTP Cyclohydrolase)
RN  - EGX657432I (sapropterin)
SB  - IM
MH  - Adult
MH  - Biopterins/analogs & derivatives/biosynthesis
MH  - Exudates and Transudates/chemistry/radiation effects
MH  - Female
MH  - GTP Cyclohydrolase/radiation effects
MH  - Humans
MH  - Male
MH  - Phenylalanine Hydroxylase/metabolism/radiation effects
MH  - Pigmentation Disorders/*prevention & control
MH  - Pteridines/*therapeutic use
MH  - Skin Diseases, Vesiculobullous/metabolism
MH  - Time Factors
MH  - Tumor Necrosis Factor-alpha/analysis
MH  - Ultraviolet Rays
EDAT- 1997/07/01 00:00
MHDA- 1997/07/01 00:01
CRDT- 1997/07/01 00:00
PHST- 1997/07/01 00:00 [pubmed]
PHST- 1997/07/01 00:01 [medline]
PHST- 1997/07/01 00:00 [entrez]
AID - S0022-202X(15)42942-2 [pii]
AID - 10.1111/1523-1747.ep12276418 [doi]
PST - ppublish
SO  - J Invest Dermatol. 1997 Jul;109(1):31-5. doi: 10.1111/1523-1747.ep12276418.