Steroid hormone serving as an immunosuppressor often induces immunotoxicity when administered in highest dosage or accumulated in long-term usage. The stage of high concentration of steroid hormone leading to a wide range of symptoms is associated to the yang.deficient state, which is the part of yin-yang imbalance involved in processes of many diseases in traditional Chinese medicine. Here we intend to investigate the profile of Th1/Th2- related cytokine transcriptions under yang-deficient conditions in a yang-deficient animal model by intramuscular injection of hydrocortisone （a kind of steroid hormone）. The yang.deficient symptoms were estimated by detecting activity, appetite, body weight and so on. T cell proliferation and cytokine transcriptions were analyzed. The results showed that yang-deficient mice were established successfully since typical yang.deficient symptoms were observed in this model with decreased activities, appetite, body weight and temperature. More interestingly, the transcriptions of IFN-γ, IL-2, IL-4 and IL-10 in this model were markedly suppressed and the proliferation of lymphocytes significantly decreased as well. The results suggested thatyang-deficient symptoms were related to the steroid-induced reduction of cytokine transcription and impairment of lymphocyte proliferation. Therefore, novel strategies through regulating cytokine production might be considered as potent approach to patients with yang.deficiency symptoms.
