# PHOTODERMATOLOGICAL STUDIES

> **NIH NIH R01** · LOVELACE RESPIRATORY RESEARCH INSTITUTE · 1988 · $95,681

## Abstract

The marsupial Monodelphis domestica represents a novel animal model with
which to study the role of a specific ultraviolet radiation (UVR)-induced,
DNA lesion in the photobiology of mammalian skin.  As in humans, cells in
the epidermis of M. domestica have a high capacity for the
photoreactivation (PR) of UVR-induced pyrimidine dimers.  This
light-dependent, repair pathway has the unique property of acting only on
pyrimidine dimers and if PR decreases the ability of UVR to induce a
photobiological response it is definitive evidence that pyrimidine dimers
are involved in the induction of that response.  The ability to correlate
UVR-induced molecular lesions with photobiological responses of the skin
will contribute valuable information to the field of dermatology,
especially those areas involved with pathological conditions of the skin.

The long-term objective of this project is to use the PR capacity present
in cells of marsupial skin to study the role, and possible site of action,
of UVR-induced pyrimidine dimers in photobiological responses of mammalian
skin.  The specific aims are:  1) determine action spectra for the
induction of pyrimidine dimers in dermal and in epidermal DNA.  A
concordance between one of these action spectra with an action spectrum for
induction of phototoxic reactions will be indicative of the site (dermal
vs. epidermal) of induction of phototoxicity; 2) determine optimal
conditions for the photoreversal of pyrimidine dimers in the epidermal DNA
of M. domestica; 3) use PR to determine the role of pyrimidine dimers in
UVR-induced pertubations of cell cycle kinetics and histopathological
changes in mammalian skin; 4) carry out split treatment studies in which
the UVR exposure is separated from the PR treatment by increasing periods
of time.  The kinetics of the decay in the ability to photoreactivate the
induction of a phototoxic reaction may be indicative of the kinds of early
reactions that occur in the expression of phototoxic events.

## Key facts

- **NIH application ID:** 3157192
- **Project number:** 5R01AR035442-03
- **Recipient organization:** LOVELACE RESPIRATORY RESEARCH INSTITUTE
- **Principal Investigator:** RONALD D LEY
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $95,681
- **Award type:** 5
- **Project period:** 1986-09-01 → 1989-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3157192

## Citation

> US National Institutes of Health, RePORTER application 3157192, PHOTODERMATOLOGICAL STUDIES (5R01AR035442-03). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3157192. Licensed CC0.

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