Effects Of Prenatal DEHP Exposure On Expression Of Circadian-related Genes In Hypothalamus Of Adult Offspring Rat

Objective:To investigate the potential effect of prenatal DEHP exposure on circadian rhythms of rats,the expression level of Clock,Arntl,Dbp,Per1,Per2 genes in hypothalamus and the expression level of CLOCK and DBP protein in SCN and cerebral cortex of adult offspring rats were detected.Methods:32 pregnant rats were randomly divided into four groups?n=8 per group?and treated with corn oil?vehicle control?and 2,10,50mg/kg DEHP by gavage from gestational day 14 to 19.The dosing volume was 10mL/kg day.Postnatal day 0?PND0?was determined by the birth of pup.From PND21,the pups were weaned and separated by sex.When the offspring rats reached the age of 10 weeks,1 male and 1 female rats per litter?n=8 per sex per group?were randomly chosen.After decapitation,brains were removed quickly and were cut into 1mm slices with stainless steel brain matrices.Based on The Rat Brain in Stereotaxic Coordinates(6^th),bilateral micropunches?1.25 mm diameter?were taken from the SCN and the RNA were extracted.The real-time quantitative PCR were used to detect the relative expression level of circadian-related genes.Using the same methods to chose 8 offspring rats in each group.After fixation,the brain were removed and sliced into 40?m slices using a vibrating blade microtome.Immunohistochemistry and confocal laser scanning microscope were used to detect the relative expression level of CLOCK and DBP protein in SCN and cortex.Results:?1?There was no significant difference in the SCN Clock gene expression level of male rats among the treatment groups and the control group?F=0.200,P=0.896?.The SCN Clock gene expression level of female rats among the treatment groups and the control group was significantly different?F=5.390,P=0.007?.Compared with the control group,the SCN Clock gene expression level of the the 50mg/kg DEHP treated female rats was increased?P<0.05?.?2?There was no significant difference in the SCN Arntl gene expression level of male rats among the treatment groups and the control group?F=0.293,P=0.830?.There was no significant difference in the SCN Arntl gene expression level of female rats among the treatment groups and the control group?F=0.688,P=0.569?.?3?The SCN Dbp gene expression level of male rats among the treatment groups and the control group was significantly different?F=4.179,P=0.015?.Compared with the control group,the SCN Dbp gene expression level of the 10 and50mg/kg DEHP treated male rats were decreased?P<0.05?.There was no significant difference in the SCN Dbp gene expression level of female rats among the treatment groups and the control group?F=1.837,P=0.170?.?4?There was no significant difference in the SCN Per1 gene expression level of male rats among the treatment groups and the control group?F=0.341,P=0.796?.The SCN Per1 gene expression level of female rats among the treatment groups and the control group was significantly different?F=3.535,P=0.031?.Compared with the control group,the SCN Per1 gene expression level of the 50mg/kg DEHP treated male rats was increased?P<0.05?.?5?There was no significant difference in the SCN Per2 gene expression level of male rats among the treatment groups and the control group?F=0.673,P=0.576?.There was no significant difference in the SCN Per2 gene expression level of female rats among the treatment groups and the control group?F=0.688,P=0.569?.?6?The SCN CLOCK protein expression level of male rats among the treatment groups and the control group was significantly different?F=3.271,P=0.043?.Compared with the control group,the SCN CLOCK protein expression level of the 2 and 50mg/kg DEHP treated male rats were decreased?P<0.05?.The SCN CLOCK protein expression level of female rats among the treatment groups and the control group was significantly different?F=4.283,P=0.017?.Compared with the control group,the SCN CLOCK protein expression level of the 2 and 50mg/kg DEHP treated female rats were increased?P<0.05?.?7?There was no significant difference in the CLOCK expression level in the cortex of male rats among the treatment groups and the control group?F=0.798,P=0.510?.There was no significant difference in the CLOCK expression level in the cortex of female rats among the treatment groups and the control group?F=0.743,P=0.539?.?8?There was no significant difference in the SCN DBP expression level in the cortex of male rats among the treatment groups and the control group?F=2.199,P=0.121?.There was no significant difference in the SCN DBP expression level in the cortex of female rats among the treatment groups and the control group?F=2.045,P=0.140?.Conclusions:?1?Prenatal DEHP exposure may interupt the circadian reguation by altering the expression level of some of the SCN circadian-related genes and proteins.?2?The effect of prenatal DEHP exposure on SCN circadian-related genes may related to exposure level.?3?The effect of prenatal DEHP exposure on circadian rhythm showed gender dimorphic.