Effects of double UVB-irradiations with different intervals on the dorsal skin of wistar-derived hypotrichotic WBN/ILA-Ht rats

Exp Toxicol Pathol. 2001 Jun;53(2-3):107-14. doi: 10.1078/0940-2993-00170.


The effects of double irradiations of UVB (10 kJ/m2) with different intervals (12, 24 and 48 hr) were examined on the dorsal skin of Wistar-derived hypotrichotic WBN/ILA-Ht rats as the first step for long-term repeated irradiation study. The dorsal skin responses to a single UVB-irradiation were similar to those previously reported by our research group (Exp Toxicol Pathol, in press). In the groups which were given the 2nd irradiation at 12 and 24 hr after the 1st one, erythema, epidermal damage and subsequent hyperplasia, intradermal inflammatory cell infiltration and edema developed earlier and were more prominent especially in 12 hr-group compared with a single irradiation. However, the sequence of sunburn cells, the most characteristic epidermal change, was not different from that after a single irradiation. On the other hand, the dorsal skin responses to the 2nd irradiation at 48 hr after the 1st one were almost similar to those observed in the single irradiation-group except for epidermal hyperplasia being more prominent in 48 hr-group. This suggests that the responsibility of the dorsal skin almost recovered at 48 hr after the 1st irradiation.

MeSH terms

  • Animals
  • Apoptosis / radiation effects
  • Cell Count
  • DNA Fragmentation
  • Edema / etiology
  • Edema / pathology
  • Erythema / etiology
  • Erythema / pathology
  • Hyperplasia / etiology
  • Hyperplasia / pathology
  • Hypotrichosis / congenital
  • Hypotrichosis / metabolism
  • Immunoenzyme Techniques
  • In Situ Nick-End Labeling
  • Keratinocytes / pathology
  • Keratinocytes / radiation effects
  • Male
  • Mast Cells / cytology
  • Mast Cells / radiation effects
  • Proliferating Cell Nuclear Antigen / analysis
  • Radiation Injuries, Experimental / pathology*
  • Rats
  • Rats, Nude
  • Rats, Wistar
  • Skin / pathology*
  • Skin / radiation effects
  • Skin Diseases / etiology
  • Skin Diseases / pathology*
  • Time Factors
  • Ultraviolet Rays / adverse effects*


  • Proliferating Cell Nuclear Antigen