DEVELOPMENTAL IMMUNOTOXICOLOGY ASSESSMENT IN THE RAT: AGE, GENDER, AND STRAIN COMPARISONS AFTER EXPOSURE TO LEAD

Abstract

A delayed-type hypersensitivity response (DTH) measured against keyhole limpet hemocyanin (KLH) and an enzyme-linked immunosorbant assay (ELISA) for anti-KLH IgG antibody were studied for potential use as biomarkers for the assessment of immunotoxicity after exposure to a xenobiotic during fetal development. Age, gender, site of antigenic challenge, and strain of rat were used as variables. The heavy metal lead was used because it is a known developmental immunotoxin. In the age comparison, untreated juvenile (5-week-old) SpragueDawley (CD) rats produced lower levels of antibody and showed a smaller DTH response than adults; only adult males had a statistically significant increase in the DTH response. Both male and female adults showed a statistically significant increase in levels of antibody over those of both genders of weanlings. As to site of KLH challenge, the DTH response was greater in untreated young animals when they were challenged in the footpad rather than the earlobe. Gender differences in ...