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17beta-estradiol enhances contact hypersensitivity in a hair cycle-dependent manner and retards thymic atrophy with
Fumitoshi Sakazaki1, Hitoshi Ueno, Katsuhiko Nakamuro
1Department of Public Health & Preventive Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Osaka, Japan.
Abstract:
The effect of 17beta-estradiol (E2) on murine contact hypersensitivity (CHS), thymic atrophy, and hair-cycle change related to growth was investigated. Female mice were ovariectomized. E2 (3.2 microg) was injected subcutaneously along with the sensitizer 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one (OXA), and a hypersensitive reaction was elicited with OXA on the ear in mice of various ages. E2 enhanced allergy only in 3- and 7-week-old mice, just prior to hair regrowth. Age-related thymus atrophy was repressed in the E2-treated mice compared with the control mice. E2 alone did not cause thymus involution, but it did inhibit thymus involution and regeneration after CHS.
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