Effect of a bacterial lipopolysaccharide treatment on rabbit testis and ejaculated sperm

In a previous study, we reported the short- and long-term effects of bacterial lipopolysaccharide (LPS)-induced inflammation on rabbit sperm quality. This study was aimed at exploring the spermatogenesis of the rabbit model focussing on the possible damages occurring to the testis and ejaculated sperm. Twenty New Zealand White rabbit bucks were divided into two groups. One group was inoculated intra-peritoneally with LPS, the other group, considered as control, was treated under the same conditions with saline only. Semen samples were collected before LPS injection, the 7th, 14th, 21st, 30th, 45th, 60th and 90th day after LPS treatment. Semen parameters were evaluated following international guidelines. The kinetic characteristics of ejaculated sperm were analysed using a computer-assisted sperm analyzer and the ultrastructural characteristics were explored by transmission electron microscopy (TEM). On the 7th, 14th and 30th day, testis from treated rabbits and controls were obtained. Testis samples were analysed by light microscopy and TEM. The induced LPS lesions in the testis became evident the 7th day after treatment, with a decrease in germinal cells and with an increase in structurally altered Sertoli cells; normal spermatogenesis was restored on the 30th day. The testicular damages observed on day 7 were probably responsible for the reduction in sperm concentration and motility and the ultrastructural alterations that were detected in the ejaculated sperm on the 14th through the 30th days after treatment. In conclusion, rabbit buck treated with LPS could be a useful model for studying the effect of an induced systemic inflammation on spermatogenesis.