Comparison of tissue sources for the skin integrity function test (SIFT)

One of the in vitro models involved in an ECVAM-sponsored prevalidation stu dy for acute skin irritation is the skin integrity function test (SIFT), wh ich utilises full-thickness mouse skin. We have evaluated nine different sk in types in order to identify the most useful model for assessing skin barr ier function using transepidermal water loss (TEWL), electrical resistance (ER) and tritiated water flux (TWF) and sodium lauryl sulphate (SLS) as a s tandard skin irritant. Tissues were: human skin (epidermis and whole), reco nstituted human epidermis (RHE), pig (dermatomed and whole), rabbit (whole) , rat (epidermis and whole) and mouse (whole). Barrier function was measure d following sodium lauryl sulphate (SLS) exposure and expressed as a damage ratio. Human epidermis gave good responses at high doses of SLS only. RHE had abnormally high permeability to water and therefore had little or no re sponse to SLS. Pig skin gave low TEWL ratios and rabbit skin was a poor res ponder to SLS. Mouse whole skin performed best in this study, giving consis tent high damage ratios to TEWL, ER and TWF following SLS treatment. Rat wh ole skin also performed well but was generally less responsive. We conclude that mouse skin is the best and most practical in vitro model for the SIFT approach for skin irritation prediction. (C) 2001 Elsevier Science Ltd. Al l rights reserved.