Study On The Toxicity Of PFOS To The Reproductive System Of Adult Quail

ObjectivePerfluorooctane sulfonate(PFOS,C₈F₁₇SO₃^-)is a kind of synthetic perfluorinate compounds(PFCs).The widespread use of PFOS and its related products,as well as the environmental stability of the perfluorinated organic chemical,have led to documentation of its presence in both human and wildlife populations worldwide.The toxicity of PFOS to mammals has been investigated in rats,mice,rabbits,and monkeys. The results indicated that there are some reproductive and developmental toxicity in these mammals exposure to PFOS.There are few researches on the toxicity of PFOS to birds.Newsted et.al fed juvenile mallard and quail with PFOS and reported marked reduction of body weight and feed consumption,and the mortality is increased.They also estimated the LD₅₀and the half-life of PFOS.They didn't evaluate the reproductive effect of PFOS.Currently,there has no study on the effects of PFOS in birds yet in China.This experiment is to determine the toxicity of PFOS to the reproductive system of adult quail.Methods70 adult female quail was randomly assigned to one control(20 birds)or five treatment(10 birds / treatment)groups by weight.60 adult male quail was randomly assigned to one control(10 birds)or five treatment(10 birds / treatment)groups by weight.Control and treatment groups were fed PFOS in their diet for 15 days, mentioned as exposure period in following context.The concentration was 0,12.5,25, 50,100 or 200mg/kg feed,respectively,and part of the birds were sacrificed on Day 16 of the trial.Then the remaining birds were then observed for 15 days while being given uncontaminated feed,mentioned as recovery period in following context.All the survival quail were euthanized on Day 31 of the trial.Recorded the weight and feed consumption each 3 days,observed daily for abnormal behavior,physical injury,or mortality,as well as the amount of egg laying and the weight of eggs of the female quail in each group.All birds that died during the test were subjected to weighted and gross necropsy.In addition,removed the ovaries of female quail and the testis of male quail,observe gross alteration,weighted,then fixed the testis with 10%formaldehyde, H-E staining,evaluated histological alteration.ResultsIn the 100 mg/kg treatment group,the only treatment-related mortality was noted at Day 10.In the 200mg/kg treatment group,first treatment-related mortalities were noted at Day 9 in both male and female quail.In the 100 and 200 mg/kg treatments, signs of toxicity were observed in Day 6 and 4,respectively.The statistically significant reductions in body weight of 200mg/kg treatment female quail occurred at Day 3,and recovered to control level by the end of the trial.In the 200 and 100 mg/kg treatments male,body weight statistically significant reduced when compared to control by Day 6 and Day 11,respectively,and recovered to control level by Day 27.In the 50,200 mg/kg treatments female and 25 mg/kg or greater treatments male,the feed consumption was statistically significant lower than control group.Statistically significant reduction in food utilization rates were observed in both female and male birds exposed to dietary concentrations of 200 mg PFOS/kg feed when compare to controls,and were negative.In the recovery period,the food utilization rate of the female quail in 200 mg/kg group was rapid increase,and significant higher than that of control.In the highest treatment group,female ovaries and male testis weight was significant reduced when compared to controls,after the recovery period,the female ovaries weight recover to the control level,the survival male quail's testis weight have no significance compared with controls.The relative weight of female ovaries have a decreasing trend with PFOS dose rising,but have no statistically significance.In the 200 mg/kg treatment male,the relative weight of testis significant lower than control. During the exposure period,the average weight of eggs in 50,100,and 200 mg/kg treatments was significant decreased compared to control,the average laying rate in 200 mg/kg treatment was lower than control.There was no developmental follicle in the 200 mg/kg treatment female at the end of the exposure period,the development of follicle in other treatment groups correspond to the control,at the end of the recovery period,the development of follicle in all treatment groups correspond to the control. There was one reduction of testis size in the 100 mg/kg treatment group,and three reductions of testis size in the 200 mg/kg group after expose to the PFOS.Exposed to PFOS conduct morphology alternate of male testis.Conclusion1.The early toxicity representation of quail to PFOS exposure was appearance and behavior alternate,include ruffled appearance,reduce reaction to stimuli,lethargy, wing droop,loss of coordination and lower limb weakness;Exposure to PFOS reduce body weight,feed consumption and food utilization rates of quail,and can rapidly recover after remove the treatment factor.Mortality and toxicity representation was more incidental in male than female.2.The reproductive organ weight and relative weight were decreased when expose to high PFOS dose;3.Expose to high PFOS dose can lose egg's weight and laying rate,and can effect follicular development of female quail;4.PFOS can reduce the testis size of male quail,and can conduct morphology alternate the testis.