Excessive additive iodine intake reduces sperm production and induces sperm deformity in male rats in early development

Objective:To investigate the effect of excessive additive iodine intake on reproductive organs of male weanling rats. Methods:One hundred and three male weanling rats were fed with feedstuff containing 0,0.5.1.2.5,and 5- fold higher dosage of iodine in standard iodine-additive salt,i.e.200,300,400,700,and 1200μg/kg,respectively, for 130-136 days.The number of rats taking different dosages of iodine was 20,21,21,21,20 respectively.The rats fed 200μg/kg of iodine were taken as the control group.For all groups,their structural changes of reproductive organs and sperm quality were evaluated. Results:The three experiment groups fed with 1,2.5,and 5-fold higher dosage iodine showed apparent reduction in testicular weight(P<0.05-0.01) by 10.76%,14.58%and 25.35%,respectively,compared with the control. But significant reduction in testis/body weight ratio was only observed in the 5-fold higher dosage group.The sperm concentration and total sperm count declined in four experiment groups fed with 0.5-5 fold higher dosage of iodine.The sperm concentration was reduced by 6.59%,22.53%,17.35%and 18.06%respectively.The percentage of sperm with normal and abnormal form significantly changed(P<0.05).The addition of different doses of iodine showed no apparent adverse effects on other reproductive organs or sperm viability. Conclution:These results indicated that excessive iodine intake might cause potential hazards on reproductive organs of male rats with respect to spermatogenesis.

Objective： To investigate the effect of excessive additive iodine intake on reproductive organs of male weanling rats. Methods： One hundred and three male weanling rats were fed with feedstuff containing 0, 0.5, 1, 2.5, and 5- fold higher dosage of iodine in standard iodine-additive salt,i, e. 200, 300, 400, 700, and 1200 μg/kg, respectively, for 130-136 days. The number of rats taking different dosages of iodine was 20, 21, 21, 21, 20 respectively. The rats fed 200 μg/kg of iodine were taken as the control group. For all groups, their structural changes of reproductive organs and sperm oualitv were evaluated. Results： The three experiment groups fed with 1, 2.5, and 5-fold higher dosage iodine showed apparent reduction in testieular weight （P〈0. 05-0. 01） by 10.76%, 14.58% and 25.35%, respectively, compared with the control. But significant reduction in testis/body weight ratio was only observed in the 5-fold higher dosage group. The sperm concentration and total sperm count declined in four experiment groups fed with 0.5-5 fold higher dosage of iodine. The sperm concentration was reduced by 6.59%, 22.53%, 17.35% and 18.06% respectively. The percentage of sperm with normal and abnormal form significantly changed （P〈0.05）. The addition of different doses of iodine showed no apparent adverse effects on other reproductive organs or sperm viability. Conclution： These results indicated that excessive iodine intake might cause potential hazards on reproductive organs of male rats with respect to spermatogenesis.