Sensitivity and subsequent "down regulation" of sensitivity induced by chlorocresol in guinea pigs.
Chlorocresol was shown to have great potential for contact sensitization in the guinea-pig maximization test at the Day-21 challenge; 2 weeks later, the reactivity was significantly decreased. Cyclophosphamide (250 mg/kg) was interperitoneally injected and used as a modulator for the immune response. When cyclophosphamide was administered 3 days before the first challenge, the decrease in reactivity from Day 21 to Day 35 was reversed. This indicates that the reduction in sensitivity was caused by an immunologic mechanism--probably the formation of suppressor cells. This phenomenon is called the "down regulation" of sensitivity and may operate in eczema patients who have lost patch-test reactivity.
D000818:Animals; D003408:Cresols / Q000633:toxicity*; D003520:Cyclophosphamide / Q000494:pharmacology; D003877:Dermatitis, Contact; D004890:Erythema; D005260:Female; D006168:Guinea Pigs; D012882:Skin Tests
D003408:Cresols; C006984:chlorocresol; D003520:Cyclophosphamide