The overall objective of this work is to understand the photobiological mechanisms involved in chronic environmental UV damage to mammalian skin in a manner sufficient to accurately explain and predict the photobiological consequences of on-going ozone depletion on chronic epidermal and dermal damage, including photocarcinogenesis and """"""""photoaging."""""""" Observed action spectra are dose- and time-dependent (""""""""dynamic""""""""), mainly due to UV-induced hyperplasia. Correction for this effect allows construction of """"""""intrinsic"""""""" action spectra that can be convoluted with various solar spectral distributions (including those which simulate changes due to stratospheric ozone depletion) to afford """"""""biologically effective doses"""""""" under the various atmospheric conditions. Specifically, we wish to (l) expand ongoing photobiological studies in Sk-1 hairless mice to include clinical, histological, and biochemical responses as a function of total dose, wavelength, and dose delivery. We will monitor UV-induced increases in pyrimidine dimers, acid glycosminoglycans (GAG), and changes in collagen structure and fluorescence properties. (2) Construct action spectra for UV-induced DNA and dermal damages. These will be """"""""corrected"""""""" for non-uniform absorption of incident radiation by inert stratum corneum-epidermis, to afford """"""""intrinsic"""""""" action spectra. (3) Compare the effect of broad- vs. narrow band radiation on the dose-response and action spectra obtained above (test for UVA/UVB waveband interactions). In addition to providing fundamental photochemical and biochemical information, the mechanistic insight provided by these studies should enable more accurate explanation and prediction of photobiological consequences of ozone depletion or other atmospheric changes which would alter the amount of solar UV in the environment.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
5R01ES007202-02
Application #
2156400
Study Section
General Medicine A Subcommittee 2 (GMA)
Project Start
1994-09-30
Project End
1997-09-29
Budget Start
1995-09-30
Budget End
1996-09-29
Support Year
2
Fiscal Year
1995
Total Cost
Indirect Cost
Name
Morehouse School of Medicine
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
City
Atlanta
State
GA
Country
United States
Zip Code
30310
Menter, J M; Patta, A M; Hollins, T D et al. (1998) Photoprotection of mammalian acid-soluble collagen by cuttlefish sepia melanin in vitro. Photochem Photobiol 68:532-7
Menter, J M; Hollins, T D; Sayre, R M et al. (1998) Protection against photodynamic therapy (PDT)-induced photosensitivity by fabric materials. Photodermatol Photoimmunol Photomed 14:154-9
Menter, J M; Willis, I (1997) Electron transfer and photoprotective properties of melanins in solution. Pigment Cell Res 10:214-7
Menter, J M; Sayre, R M; Etemadi, A A et al. (1996) Chronic exposure of Sk-1 hairless mice to narrow-band ultraviolet A (320-355 nm) Photodermatol Photoimmunol Photomed 12:7-11
Menter, J M; Williamson, G D; Carlyle, K et al. (1995) Photochemistry of type I acid-soluble calf skin collagen: dependence on excitation wavelength. Photochem Photobiol 62:402-8