Effects Of Low Dose Cadmium Intake During Pregnancy On Placental Function

Cadmium is the important pollutant and harmful to human health.Cadmium can enter human body in many ways,and dietary cadmium intake is the main form of cadmium intake.The pollution of cadmium to food is mainly caused by the discharge of industrial wastewater.The industrial wastewater containing cadmium pollutes the water body,and the concentration of aquatic organisms makes the cadmium content in aquatic products increase significantly.The results showed that the cadmium residue in food was higher than that in plant food,especially in seafood and animal food(especially in kidney),and the content of cereal,rhizome and legume in plant food was higher.The use of cadmium containing metal as a container for acidic food or drink makes people come into contact with cadmium through diet.The metabolism of cadmium in human body is slow and the excretion rate is low,and with the blood flow.It accumulates in many organs in the body,which causes a variety of serious influence on these organs.Among them,cadmium has strong reproductive toxicity to reproductive organs.On the one hand,it can lead to necrosis of male testis and epididymis tissue,and insufficient secretion of ovarian hormones.On the other hand,it can lead to many adverse pregnancy outcomes by inhibiting the normal development and function of placenta,such as preeclampsia,fetal growth restriction and so on.As an important temporary endocrine organ during pregnancy,placenta has the functions of invasion,immune protection,nutrition transportation,endocrine and so on.Among them,the latter two are related to fetal growth,which the researchers were insterested in.However,the effects of cadmium on placental function,especially on nutrient transport function and endocrine function,are still unclear.Based on this,this study will explore effects of cadmium on placental nutrient transport function and hormone secretion function and its molecular mechanism.In the first part,the expression level of placental amino acid transport vector and the content of amino acid in plasma of mice with low dose cadmium intake during pregnancy were detected to explore the effect of cadmium on the nutritional transport function of placental amino acids and its molecular mechanism.By detecting the changes of estrogen and progesterone concentration in plasma and placenta of mice with low dose cadmium intake during pregnancy and the m RNA expression level of progesterone synthesis related enzymes,the mechanism of cadmium's influence on placental hormone secretion was explored.This study provides a powerful experimental basis for the prediction,evaluation and protective treatment of cadmium risk in human health during pregnancy.The following conclusions were obtained from the above experiments:(1)Low dose cadmium intake during pregnancy can inhibit the transport function of placental amino acids,which may be related to the decrease m RNA LAT1 gene expression and protein expression in placenta.Decrease of amino acid concentration in plasma of cadmium exposed mice may be an important inducement to decrease the expression level of amino acid transport carriers such as LAT1 in placenta.(2)Low dose cadmium intake during pregnancy can inhibit the function of placental hormone secretion,which can lead to the decrease of progesterone content in the placenta and maternal blood of mice,which may be related to the imbalance of progesterone synthase HSD3B1 expression,but not to the level of progesterone synthesis substrate(cholesterol)in placenta.