Abstract
The aim of the present study was to investigate the role of the pituitary in the delayed-type hypersensitivity (DTH) response in mice. We examined the effect of hypophysectomy on 2, 4, 6-trinitrochlorobenzene (TNCB) -induced DTH, which has been used as a cellular immunity model in vivo. Seven-week-old male BALB/c and C57BL/6 mice were used. Six days after sensitization with TNCB, TNCB was applied to the left ear pinnea and the DTH response was measured as the degree of ear swelling 24 hours after TNCB challenge. The TNCB-DTH reaction was also measured 24 hours after intracisternal injection of α-helical coricotropin-releasing factor (CRF), a CRF inhibitor, at doses of 0.4, 1, 5, and 10 μg. Maximal ear swelling in both hypophysectomized mice and mice that received α-helical CRF was significantly increased. Histologically, adrenocortical atrophy and deposition of lipid were observed in hypophysectomized mice at the time DTH was enhanced. These results suggest that pituitary ACTH plays a suppressive role in the DTH response in mice.
