Abstract: Abstract Objective To study the effects of fluorosis of coal burning on reproductive and endocrinology of male rats. Methods SD rats taken as the experimental objects were randomly assorted into 7 groups: control group，low-dose fluoride group, middle-dose fluoride group, high-dose fluoride group, low-dose fluoride supplemented with nutrition group，middle-dose fluoride supplemented with nutrition group and high-dose fluoride supplemented with nutrition group. The exposed groups were fed with the fodder with different proportions of corn dried by burning coal coming from endemic fluorosis areas, to establish the animal model of coal-burning fluorosis. All rats were killed by femoral arterial exsanguination at three times（90d,120d，180d）. Followed by examinations of dental fluorosis，fluorine in urine and the concentrations of intratesticular testosterone and testosterone (T), estradiol (E2)，luteinizing hormone (LH), follicle stimulating hormone (FSH), Gonadotropin-Releasing Hormone (GnRH)and Prolactin（PRL） in serum. Results The animal model of fluorosis was successfully established. Compared with the control groups, the level of T, E2 and PRLdeclined more apparently with the increasing fluoride dose and the longer exposure time in exposed groups（p<0.05 or p<0.01）,but the level of LH and FSH increased more apparently with the increasing fluoride dose and the longer exposure time in exposed groups（p<0.05 or p<0.01）. Compared with the control groups, the level of exposed groups’GnRH declined more apparently with the longer exposure time but increased more apparently with the increasing fluoride dose between exposed groups（p<0.05 or p<0.01）. In the same dose of fluoride added nutrition groups sex hormone levels improved (p <0.05 or p <0.01). Conclusions Coal-burning fluorosis had a significant endocrine effect on reproductive and endocrinology of male rats, with the increasing fluoride dose and prolonged exposure, influence increased. Reducing fluoride intake and improving nutritional status can ease the effects of coal-burning fluorosis on reproductive and endocrinology of male rats.

Key words: reproductive and endocrinolog, fluorosis of coal burning, male rats