Melanosomes are a primary target of Q-switched ruby laser irradiation in guinea pig skin

Journal Article · Tue Sep 01 00:00:00 EDT 1987 · J. Invest. Dermatol.; (United States)

DOI:https://doi.org/10.1111/1523-1747.ep12471397· OSTI ID:6086977

Polla, L L; Margolis, R J; Dover, J S; Whitaker, D; Murphy, G F; Jacques, S L; Anderson, R R

The specific targeting of melanosomes may allow for laser therapy of pigmented cutaneous lesions. The mechanism of selective destruction of pigmented cells by various lasers, however, has not been fully clarified. Black, brown, and albino guinea pigs were exposed to optical pulses at various radiant exposure doses from a Q-switched, 40 nsec, 694 nm ruby laser. Biopsies were analyzed by light and electron microscopy (EM). Albino animals failed to develop clinical or microscopic evidence of cutaneous injury after irradiation. In both black and brown animals, the clinical threshold for gross change was 0.4 J/cm2, which produced an ash-white spot. By light microscopy, alterations appeared at 0.3 J/cm2 and included separation at the dermoepidermal junction, and the formation of vacuolated epidermal cells with a peripheral cytoplasmic condensation of pigment. By EM, enlarged melanosomes with a central lucent zone were observed within affected epidermal cells at 0.3 J/cm2. At 0.8 and 1.2 J/cm2, individual melanosomes were more intensely damaged and disruption of melanosomes deep in the hair papillae was observed. Dermal-epidermal blisters were formed precisely at the lamina lucida, leaving basal cell membranes and hemidesmosomes intact. Possible mechanisms for melanosomal injury are discussed. These observations show that the effects of the Q-switched ruby laser are melanin-specific and melanin-dependent, and may be useful in the selective destruction of pigmented as well as superficial cutaneous lesions.

• Research Organization: Massachusetts General Hospital, Boston
• OSTI ID: 6086977
• Journal Information: J. Invest. Dermatol.; (United States), Vol. 89:3
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
62 RADIOLOGY AND NUCLEAR MEDICINE
LASER RADIATION
BIOLOGICAL EFFECTS
ANIMAL CELLS
ELECTRON MICROSCOPY
EPIDERMIS
GUINEA PIGS
MELANIN
RUBY LASERS
SKIN
SURGERY
ANIMAL TISSUES
ANIMALS
BODY
ELECTROMAGNETIC RADIATION
EPITHELIUM
HYDROXY COMPOUNDS
LASERS
MAMMALS
MEDICINE
MICROSCOPY
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PIGMENTS
RADIATIONS
RODENTS
SOLID STATE LASERS
TISSUES
VERTEBRATES
560400* - Other Environmental Pollutant Effects
550600 - Medicine