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Updated: Aug 16, 2026
Induction and Monitoring of Adoptive Delayed-Type Hypersensitivity in Rats
Published on: October 1, 2007
Comparable effects of adrenalectomy and C fiber depletion on delayed-type hypersensitivity in rats
1Department of Integrative Physiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. kataf@physiol.med.kyushu-u.ac.jp
Objective:
To determine the influence of the hypothalamic-pituitary-adrenal (HPA) axis and sensory C fibers on cell-mediated immunity, the time course of allergic contact dermatitis (ACD) was examined in normal, adrenalectomized (ADX) and capsaicin (CAP)-treated rats.
Methods:
Five days after sensitization with 2,4-dinitro-1-fluorobenzene (DNFB) onto the back, rats were challenged with DNFB on the pinna. ADX or CAP treatment was performed a week before the sensitization.
Results:
Ear swelling in normal rats reached a peak 24 h after the challenge and subsided gradually to about half of this peak 72 h afterwards. Plasma ACTH levels increased about 9 times more than those of nonsensitized rats 72 h after the challenge. ADX rats, in which the plasma corticosterone level was significantly lower than that in sham-operated animals, exhibited more rapid development of ACD, which reached a peak 12 h after the challenge. However, the swelling returned to about half of the maximum within 48 h. In CAP-treated rats, ACD reached a peak 6 h after the challenge and recovered quickly as in ADX rats. Plasma ACTH levels in CAP- treated rats were significantly lower than those in vehicle-treated rats.
Conclusions:
The rapid development of and recovery from ACD in ADX and CAP-treated rats, both of which showed suppression of the HPA axis, indicated a biphasic action of the HPA axis on ACD, i.e. inhibitory in the early phase but augmentative in the late phase of ACD.
