A new rat model for dermatitis: constitutional abnormalities evidenced by hematological and serum protein determinations.

Age-related and strain-specific patterns of various hematological values, differential counts of white blood cells, total serum protein concentrations and protein fractional values in ICR/d-strain rats were compared with those of two control strains, Jcl: Wistar and Jcl: SD rats from the 4th to 24th week of age, to study the factors related to chronic dermatitis. Determinations of hematological values and white blood cell differential counts revealed a definite tendency toward leukocytosis, relative neutrophilia and eosinophilia, significantly higher neutrophils/lymphocytes ratios and significant thrombocytopenia, all of which progressed with age. Levels of total protein concentrations tended to be slightly lower than those of the two control strains at most ages, but the difference was significant only between the ICR/d and Jcl: SD rats. Fractional values of gamma- and beta-globulins showed relatively higher levels, both of which persistently increased with age and in approximately inverse correlation with the changes in the fractional values of albumin. Fractional values of alpha 1-globulin showed markedly lower levels than those of both control strains at all ages. In conclusion, ICR/d-strain rats have definite constitutional abnormalities possibly playing some role in the occurrence and progression of chronic dermatitis of the "atopic" type.