In order to study the effect ofErigeron Breviscapus (EB) on proliferation of pulmonary artery smooth muscle cells (PASMC) in hypoxic porcines, immunohistochemical and MTT methods were employed to measure the proliferation of PASMC. It was found that the proliferation of PASMC in porcines was obvious, and the expression of proliferating cell nuclear antigen (PCNA) was significantly high within 48 h after exposure to hypoxia. The EB could inhibit the proliferation and the expression of PCNA in PASMC under hypoxia, but it had no effect on the proliferation and expression of PCNA in PASMC under normal condition. The EB could inhibit the proliferation and the expression of PCNA in PASMC induced by phorbol 12-myristate 13-acetate (PMA), an agonist of PKC in normal and hypoxic conditions. It was concluded that the hypoxia could enhance the proliferation and expression of PCNA in PASMC. The EB can inhibit the proliferation and expression of PCNA in PASMC under hypoxia through PKC-signal way. The EB may be used in treating the pulmonary hypertension by inhibiting the proliferation of PASMC and the pulmonary vascular remodeling.

To explore the regulatory role of protein kinase C (PKC) in the expression of Th₂ cytokines, interleukin-4 (IL-4) and interleukin-5 (IL-5) by T lymphocytes in asthma. T lymphocytes were isolated and purified from blood and bronchial alveolus lavage fluid (BALF) of each guinea pig of normal control group and asthmatic group and from peripheral blood of the asthmatic patients and normal controls, and were stimulated with PKC accelerant phorbol 12-myristate 13-acetate (PMA) and inhibitor Ro31-8220. The expression of IL-4 and IL-5 mRNA and protein was detected by using in situ hybridization staining and ELISA respectively. The expression of IL-4 and IL-5 mRNA and protein of asthmatic T lymphocytes stimulated with PMA was significantly higher than that of asthmatic T lymphocytes stimulated without PMA respectively (P<0. 01) and that of normal T lymphocytes stimulated with PMA respectively (P<0. 01). The expression of IL-4 and IL-5 mRNA and protein of asthmatic T lymphocytes stimulated with PMA and Ro31-8220 was significantly lower than that of asthmatic T lymphocytes stimulated only with PMA respectively (P<0. 01). It was concluded that PKC might participate in regulating the expression of IL-4 and IL-5 in asthmatic T lymphocytes, and the activation of PKC in T lymphocytes might play an important role in the pathogenesis of asthma.