Study On The Effect Of Environmental Estrogen Nonylphenol On The Expression Of Estrogen Receptor Beta In Colonic Mucosa Of Male Rats

Objective: To explore whether nonylphenol quasi estrogen has influence on the expression of estrogen receptor beta in colonic mucosa of male rats.Methods: 1、The experimental groups: selection of clean grade SD healthy male rats,5weeks of age, body weight(180+10) g. 1 week adaptable feeding of SD rats, 60 Wistar rats were randomly divided into five groups of which each has12 rats:(1) the negative control group(C group received corn oil gavage);(2) positive control group(Group D estrogen orally);(3) low dose group(group L NP of 50mg/kggavage);(4)the middle dose group(group M NP of 100 mg / kg gavage);(5) high dose group(group H NP of 200 mg / kg gavage). Each continuous irrigation gastric gavage for 60 days, intragastric volume for 0.5 ml / 100 g body weight; negative control group was given equal volume of corn oil; estrogen groups were given daily doses of estrogen 20 μg/kg/d; after gavage for 60 days after the last irrigation 24-hour intragastric in 10% chloral hydrate 1ml anesthesia cesarean section of a male rats abdominal active vein blood each 10 ml and cecal mucosa acquisition. 2、Indicators and methods: acquisition in all groups of male rats arterial blood high-speed centrifugal supernatant from-20℃ refrigerator frozen, to be detected, collected each cecal mucosa part made of paraffin, the part put-80 ℃ refrigerator frozen to be detected. 1. High performance liquid chromatography(HPLC) method was used to detect serum and cecal mucosa in NP content; 2.Direct chemical luminescence method was used to detect the serum levels of estradiol(E2) concentration; 3.Enzyme linked immunosorbent assay(ELISA) to detect serum estrogen receptor ER-β protein content; 4.Real-time fluorescence quantitative polymerase chain reaction(RT-PCR) method to detect the cecal mucosa ER-β m RNA expression; immune group of SP method was used to detect the male rat cecal mucosa in ER-β protein content. The content of serum NP and cecal mucosa ER-β correlation analysis.Results: 1、NP content in serum of male rats each group had significant difference, experimental exposure in NP group content was higher than the control group and the exposure group with NP irrigation stomach doses increased more significantly increased the content of serum NP, P < 0.05, the difference was statistically significant. 2、NP content in the cecal mucosa tissue of male rats each group had significant difference, experimental exposure in NP group content was higher than the control group and the exposure group with NP irrigation stomach doses increased more significantly increased content of NP in cecal mucosa, P < 0.05, the difference was statistically significant. 3、Concentration of E2 in serum of male rats each group are different, the E2 concentration in the experimental exposure group was higher than the control group and the exposure group with NP irrigation stomach doses increased more significantly increased the concentration of E2, P < 0.05, the difference was statistically significant. 4、In serum of male rats each group ER-β protein content had significant difference, the experimental exposure group, the serum levels of ER-β protein content is much lower than that in the control group and the exposure group with NP irrigation stomach doses increased ER-β protein content decreased more significantly, P < 0.05, the difference was statistically significant. 5、In all groups of male rats cecal mucosa ER-β m RNA expression levels are different, the experimental exposure group of ER-β m RNA expression level is much lower than that in the control group and the experimental group exposed to NP with irrigation stomach doses increased of ER-β m RNA expression level decreased more significantly, the difference was statistically significant, P < 0.05; among groups of male rat cecal mucosa in ER-β protein content had significant difference, the experimental exposure group of ER-β protein content is much lower than that in the control group and the exposure group with NP irrigation stomach doses increased ER-β protein content decreased more significantly, the difference is statistically significant,P < 0.05.6、In all the experimental exposure groups of male rats serum NP content and cecal ER-β protein optical density value and ER-β m RNA relative expression between both showed negative correlation(correlation coefficient was r =-0.44, r =- 0.63). The results are statistically significant,P < 0.05.Conclusion: 1、NP can destroy the level of estrogen in the body of male rats. 2、NP plays the role of estrogen like effect on the expression of ER-β in the cecal mucosa of male rats, and down regulated the expression level of ER-β m RNA and ER-β. 3、NP reduced the expression of ER-β may increase the risk of cecal mucosal canceration.