Topical exposure to chlordane reduces the contact hypersensitivity response to oxazolone in BALB/c mice.
Previous studies have shown that prenatal exposure to the organochlorine pesticide chlordane significantly decreases the ear swelling response to the contact allergen oxazolone in BALB/c mice. Alterations of macrophage function in the efferent arm of the contact hypersensitivity response have also been reported. In the current study, chlordane was applied topically and the effects of oxazolone-induced contact hypersensitivity were determined. Initially, the reduction in oxazolone-induced ear swelling in topically-exposed female BALB/c mice was compared to 30-day-old BALB/c female mice exposed prenatally to chlordane. Prenatal chlordane exposure induced a 36% reduction in ear swelling compared to a 60% reduction following topical treatment at the challenge phase. Topically-applied chlordane also reduced the oxazolone-induced ear swelling by 40% when applied at sensitization. When applied at both sensitization and challenge, ear swelling was reduced by 71%. In a time-course study, it was determined that chlordane must be applied at the time of sensitization, challenge or both or within 1 h post-challenge to significantly reduce ear swelling. A dose-response study showed that the lowest concentration of chlordane resulting in a significantly reduced ear swelling response was 20 micrograms per ear.
Blaylock
B L
BL
Division of Pharmacology and Toxicology, College of Pharmacy and Health Sciences, Northeast Louisiana University, Monroe 71209-0470, USA.
Newsom
K K
KK
Holladay
S D
SD
Shipp
B K
BK
Bartow
T A
TA
Mehendale
H M
HM
D000287:Administration, Topical; D000818:Animals; D002706:Chlordan / Q000008:administration & dosage / Q000633:toxicity*; D003877:Dermatitis, Contact / Q000276:immunology*; D004305:Dose-Response Relationship, Drug; D004431:Ear, External / Q000473:pathology; D004487:Edema / Q000139:chemically induced; D005260:Female; D007111:Immunity, Cellular / Q000187:drug effects*; D007306:Insecticides / Q000008:administration & dosage / Q000633:toxicity*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010081:Oxazolone / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011897:Random Allocation
D007306:Insecticides; D002706:Chlordan; D010081:Oxazolone