Abstract
External factors influencing the magnitude of contact sensitivity in mice were examined. (1) Magnitude of contact sensitivity was affected by doses of the antigens applied. Immunization with 300μg to 3 mg of oxazolone (OX) induced the greatest magnitude of contact sensitivity in A/J mice. Painting with 500μg of picryl chloride (PCl) induced the greatest magnitude of contact sensitivity in C57BL/6 mice and the contact sensitivity was reduced when miced painted with 5mg of PC1. (2) Effects of immunization by different routes were examined. Contact sensitivity with PCl did not sensitize in case of painting the clipped abdomen or tail and oral administration of PCl failed to induce contact sensitivity in mice. Painting of dinitrofluorobenzene on the clipped abdomen and footpad led to sensitization of the contact sensitivity but tail painting with the same antigen did not. (3) Effect of immunization by solvent dissolving antigens was examined. Immunization with PCl or OX dissolved with acetone induced a lesser magnitude of contact sensitivity than did immunization with other solvents such as ethanol or olive oil. It was suggested that these phenomenon were probably associated with activation of the suppressor pathway. The magnitude of contact sensitivity with PCl was reduced in the 13-month-old C57BL/6 mice.
