Experimental Study On The Effect Of Subchronic Samarium Nitrate Exposure On Reproductive System In Male Mice

China has the first storage of Rare earth element (REE) in the world. With the extensive applications of REE, biological effects of REE arouse people's intensive attention, but the effect of long-time intake of rare earth compounds on male reproductive system has been unknown. In the experiment, the weaned male mice were divided into 5 treatment groups with drinking samarium nitrate at the dose of 0, 5, 50, 500, 2000 mg/L for 90 days. By using the methods of animal behavior, biochemistry, cell biology, toxicology, morphology and histology, effect of subchronic samarium nitrate exposure on the commonly toxic symptoms, weight of body and main organs, sexual behavior, fertility test, sperm quality, biochemical indexes and trace elements contents in mice testes, testicle structure and ultrastructure of male mice were studied. The main results obtained from the experiment were summarized as follows:1. Mounting latency of mice prolonged with the dose increased after subchronic intake of samarium nitrate, and a dose-response relationship between the dose logarithm of samarium nitrate and mounting latency was evident. Mounting latency, ejaculation latency and interval were significantly increased and times of mounting and ejaculation were decreased after high dose of samarium nitrate exposure. In short, high dose of samarium nitrate intake could change sexual behavior of male mice.2. The reproductive index of male mice and fertilization rate of female mice showed a declined tendency with the dose increased. And intake of samarium nitrate could remarkablely increase the abnormality rate of embryos and shorten body length and tail length of live embryos by the paternal exposure. The results indicated that samarium nitrate intake could decrease the reproductive ability of male mice and inhibit embryonic development.3. Middle and high dose intake of samarium nitrate decreased water intake of male mice. And there was statistical difference between the control group and high dose group in weight and organ coefficient of epididymis and organ coefficient of liver. Moreover, by subchronic samarium nitrate exposure...