AIM: To study the effect of homocysteine (HCY) on proliferation of airway smooth muscle cells and fibroblasts and the effect of HCY on collagen prodution of airway fibroblasts. METHODS: [3H]-TdR incorpora- tion was measured in cultured airway smooth muscle cells. The [3H]-TdR and [3H]-proline incorporation were mea- sured in cultured airway fibroblasts. RESULTS: HCY induced proliferation of airway smooth muscle cells and fibroblasts in a concentration - dependent manner. HCY also induced collagen production of airway fibroblasts in a concentration - dependent manner. The inhibitors of protein kinase C, H7 and polymyxin B, inhibited HCY - induced proliferation of airway smooth muscle cells. CONCLUSIONS: HCY induced proliferation of airway smooth muscle cells and fibroblasts, HCY also induced collagen production of airway fibroblasts. The HCY - induced proliferation of airway smooth muscle cells may be related to the pathway of PKC signal transduction.

AIM:To study alterations of cardiac sarcoplasmic reticulum (SR) function in vitamin D 3-induced calcium overload rats. METHODS: The Ca-overload rat models were prepared by vitamin D 3 plus nicotine. Cardiac SR was seperated by centrifuging. The measurement of SR Ca 2+ uptake and Ca 2+ release activities were preformed by the Millimore filtration technique. Specific SR [ 3H]-ryanodine binding capacity was measured by radioligand method. RESULTS: Compared with control,myocardial calcium content in calcium overload rats increased by 78%( P