Animal studies have demonstrated the effect of acupuncture in modifying delayed-type hypersensitivity in mice. The swelling was reduced 45-73%, a similar figure to the suppression by steroids. The mechanism was shown to be dependent on the release of opioid peptides as well as an intact pituitary. (Kasahara 1992, 1993) Another study with mice showed a reduction in the inflammatory reaction to picryl chloride. When cells from the spleens of the treated animals were transfused into naïve mice, they too showed a similar reduction in delayed-type hypersensitivity. (Tohya 1989)

Kasahara T, Wu Y, Sakurai Y, Oguchi K 1992 Suppressive effect of acupuncture on delayed type hypersensitivity to trinitrochlorobenzene and involvement of opiate receptors. International Journal of Immuuophannacy 14(4):661-665

Kasahara T, Amemiya M, Wu Y, Oguchi K 1993 Involvement of central opioidergic and nonopioidergic neuroendocrine systems in the suppressive effect of acupuncture on delayed type hypersensitivity in mice. International Journal of Immunopharmacy 15(4):501-508.

Tohya K, Mastrogiovanni F, Sugata R et al 1989 Suppression of the DTH reaction in mice by means of moxibustion at electro-permeable points. American Journal of Chinese Medicine 17(3-4):139-144