Abstract
Male DD mice were used. The dorsolateral area of mice was irradiated with ultraviolet (wavelength : 2,537 A) from a distance of 25 cm for 20 min and the creamy paste containing vehicle only (control group A) or the creamy paste containing vitamin E (experimental group D) was applied to the exposed area 7 times successively (1 min, 6,16,28,38,58 and 60h after the ultraviolet irradiation). Then, 12h after the last application of the creamy paste (72h after the ultraviolet irradiation) tissues were excised for light and electron microscopic observations. The results obtained are summarized as follows : 1) Light microscopic findings. It was found that pathological findings showing cellular damages in the epidermis such as intracellular edema, intercellular edema, parakeratosis etc. were most prominent in the group A and very slight or none in the group D. 2) Electron microscopic findings. Cytoplasmic alterations such as widening of the intercellular space, disappearance or disintegration of desmosomes, appearance of a large number of perinuclear vacuolation, swelling of some mitochondria, cytoplasmic damages, a decrease in number of keratohyalin granules, a slight decrease in the number of free ribosomes and an increase in the number of keratinosomes in the cytoplasm were prominent in the group A. In addition, in the group A a number of keratinosomes with lamellar patterns were observed in the intercellular space in the granular and parokeratotic layers, and furthermore the characteristic remnants such as nuclei, lipid-like granules, keratinosomes etc. were prominent in the parakeratotic layer. On the other hand, in the group D a slight thickening of the stratum corneum was sometimes observed, but the remnant of the nuclei etc. was rarely found, and by and large the organelles in the irradiated epidermal cells were close to normal except for a slight increase in number of keratinosomes. From the results obtained in the present investigation, it was concluded that vitamin E is effective in either protection or restoration of epidermal cellular damages due to ultraviolet irradiation, thus possesses an antiinflammatory action. The proposed mechanism of an antiinflammatory action of vitamin E was briefly discussed.
