Ultraviolet radiation directly induces pigment production by cultured human melanocytes

Journal Article · Thu Oct 01 04:00:00 EDT 1987 · J. Cell. Physiol.; (United States)

DOI:https://doi.org/10.1002/jcp.1041330111· OSTI ID:5757658

Friedmann, P S; Gilchrest, B A

In humans the major stimulus for cutaneous pigmentation is ultraviolet radiation (UVR). Little is known about the mechanism underlying this response, in part because of the complexity of interactions in whole epidermis. Using a recently developed culture system, human melanocytes were exposed daily to a physiologic range of UVR doses from a solar simulator. Responses were determined 24 hours after the last exposure. There was a dose-related increase in melanin content per cell and uptake of /sup 14/C-DOPA, accompanied by growth inhibition. Cells from donors of different racial origin gave proportionately similar increases in melanin, although there were approximately tenfold differences in basal values. Light and electron microscopy revealed UVR-stimulated increases in dendricity as well as melanosome number and degree of melanization, analogous to the well-recognized melanocyte changes following sun exposure of intact skin. Similar responses were seen with Cloudman S91 melanoma cells, although this murine cell line required lower UVR dosages and fewer exposures for maximal stimulation. These data establish that UVR is capable of directly stimulating melanogenesis. Because cyclic AMP elevation has been associated in some settings with increased pigment production by cultured melanocytes, preliminary experiments were conducted to see if the effects of UVR were mediated by cAMP. Both alpha-MSH and isobutylmethylxanthine (IBMX), as positive controls, caused a fourfold increase in cAMP level in human melanocytes and/or S91 cells, but following a dose of UVR sufficient to stimulate pigment production there was no change in cAMP level up to 4 hours after exposure. Thus, it appears that the UVR-induced melanogenesis is mediated by cAMP-independent mechanisms.

• Research Organization: Tufts Univ., Boston, MA
• OSTI ID: 5757658
• Journal Information: J. Cell. Physiol.; (United States), Journal Name: J. Cell. Physiol.; (United States) Vol. 133:1; ISSN JCLLA
• Country of Publication: United States
• Language: English

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560120* -- Radiation Effects on Biochemicals
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINO ACIDS
AMP
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOSYNTHESIS
BODY
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CELL CULTURES
DOPA
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELECTROMAGNETIC RADIATION
EPIDERMIS
EPITHELIUM
HYDROXY ACIDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MAN
MELANIN
NEUROREGULATORS
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PIGMENTS
PRIMATES
RADIATION EFFECTS
RADIATIONS
SKIN
SYNTHESIS
TISSUES
TRACER TECHNIQUES
ULTRAVIOLET RADIATION
VERTEBRATES