ABSTRACT
<p><b>OBJECTIVE</b>To explore the changes of rat testicular spermatogenic epithelium stimulated by bacterial lipopolysaccharide (LPS) in vivo.</p><p><b>METHODS</b>Twenty Wistar rats were divided into two groups: control group and experimental group. The control group was treated with pyrogen-free saline (1 ml/kg) and the experimental group was injected ip with saline containing LPS (1 mg/kg) once every two days. Two groups were operated after ten days in order to investigate the testicular pathological changes by HE staining and the expression of proliferating cell nuclear antigen( PCNA), alpha-catenin in spermatogenic epithelium by immunohistochemistry assay.</p><p><b>RESULTS</b>The testes of the experimental group showed inflammatory changes. The positive expression of PCNA in seminiferous epithelium was significantly lower than that of control group. The number of positive cells in every seminiferous, in which only spermatogonia were stained in experimental group were 59 +/- 5 and it showed significant decrease compared with the control (P < 0.01). Furthermore, the percentage of such seminiferous tubules was 0.673 +/- 0.054 and increased apparently (P < 0.01). The expression of alpha-catenin in testicular tissue of the experimental group declined (P < 0.01), and cellular positive granular light density was 0.150 +/- 0.014.</p><p><b>CONCLUSION</b>The ability of spermatogonium proliferation and the function of conglutination of cells under inflammatory condition of the testes declined, which may be one of the etiologies of male infertility.</p>