OBJECTIVETo culture rat corpus cavernosum smooth muscle cells in vitro using a modified tissue culture method.

METHODSFifteen male rats were randomized into 3 equal groups, namely enzyme digestion group, tissue culture group, and modified tissue culture group. The penis of the rats was separated carefully and cut into small pieces, and seeded onto culture flasks and cultured in complete medium consisting of DMEM containing 20% fetal calf serum at 37 degrees C; in a humidified atmosphere with 5% carbon dioxide. The cells growth was observed under phase contrast microscope and the smooth muscle cell specific proteins alpha-SM-actin and desmin were identified immunohistochemically.

RESULTSThe alpha-SM-actin-positive cell rate was 96.3% in rat corpus cavernosum smooth muscle and 23.8% in the fibroblasts, and the corpus cavernosum smooth muscle contained 74.4% desmin-positive cells while the fibroblasts showed no desmin positivity. Significant difference was found in the positive cell rate for desmin among the 3 groups, with the highest positive cell rate occurred in modified tissue culture group.

CONCLUSIONDesmin may serve as a marker for identifying corpus cavernosum smooth muscle cells. The modified tissue culture method can result in highly purified corpus cavernosum smooth muscle cells with intact structure and functions.