RESUMEN
<p><b>OBJECTIVE</b>To explore the effect of Xiaolong Tongbi (XLTB), a Chinese herbal preparation, on nitric oxide synthase (NOS) containing nerve and epithelial cell apoptosis.</p><p><b>METHODS</b>NOS containing nerve level of various groups prostate was determined by NADPH histochemical staining and morphological quantitative analysis, and the cell apoptosis rate in rats prostatic epithelium was tested immunohistochemically with TUNEL method.</p><p><b>RESULTS</b>After 3 weeks treatment with high dose XLTB, the length density of NOS contained nerves in prostate tissue of rats was 0.113 +/- 0.023, which was significantly different to that in the other 3 groups (low dose XLTB, Finasteride and testosterone) respectively (P < 0.01). Cell apoptosis reached its peak at the day 7 of experiment in XLTB treated groups (9.27%), and Finasteride treated group (5.65%), which lowered slightly at day 14 and got some recovery at day 21. Castration induced cell apoptosis began at day 7 and reached its peak at day 14, which was significantly different from that in the other groups.</p><p><b>CONCLUSION</b>XLTB could increase the NOS contained nerve level and accelerate the apoptosis of epithelial cell in prostate tissue of simulating benign prostatic hyperplasia rats.</p>