| Objective: To simulate the smoking status of humans,establish a smoking model in rats,observe the damage effect of smoking on rat testis tissues,and analyze the mRNA and protein expression levels of Notch1 and Notch2,key signal molecules of the Notch signaling pathway,so as to explore the Notch signaling pathway in cigarette smoke Role in causing testicular toxicity.Methods: 200 adult SPF male SD rats were randomly divided into control group and low,medium and high dose exposure groups(10 rats in each group,given 0sticks/day,10sticks/day,20sticks/day,30 sticks/day).The exposure group was exposed to static respiratory infections once a day for 30 minutes each time.Rats in each group were exposed for 2,4,6,8,and 12 weeks,respectively,and the body weight of each group was recorded during the experiment.After the experiment,the testis and epididymis were observed to observe their morphology,testicular and epididymal weights were measured,their organ coefficients were calculated,and testicular tissue AKP,?-GT,?-GD,and G-6-PD activity were measured;HE staining was used to observe testicular tissue morphology IHC method was used to detect the expression of Notch1 and Notch2 in testis.RT-PCR and Western Blot were used to detect the expression of Notch1 and Notch2 mRNA and protein in testis of male rats.Results: 1.With the increase of the dose and the extension of the exposure time,the body weight of rats in each exposure group increased slowly(P<0.05);the testicular coefficient and epididymal coefficient of each exposure group showed a downward trend compared with the control group at the same period.2.HE staining results showed that the testis tissues in the poisoned group showed different degrees of pathological damage compared with the control group in the same period.3.With the increase of the exposure dose and the extension of the exposure time,the activity of AKP,?-GT,?-GD,G-6-PD in the testis tissue of each exposure group showed a downward trend(P<0.05).4.IHC results showed that compared with the controlgroup of the same period,the area of positive expression of Notch1 protein in the testis tissues began to increase in the middle-dose group at weeks 2 and 6(P<0.05),and the exposure groups at weeks 4 and 8 And the high-dose group at week 12 increased(P<0.05);the area of Notch1 protein positive expression was greater at week 12 of the control group and week 8 of the low-dose group than at week 2(P<0.05),and there was an exposed dose Interaction effect with exposure time.The area of positive expression of Notch2 protein in testis tissue was in the middle and high dose groups at weeks 2,6,and 8,the low,high dose groups at week 4,and the high dose group at week 12 were larger than the control group at the same period(P<0.05);The area of Notch2 protein positive expression was at the 6th week of the control group,the 6th week of each exposure week group of the low dose group and the medium and high dose groups was greater than the 2nd week(P<0.05),the exposure dose and exposure time existed Interaction effects.5.RT-PCR results showed that the expression level of Notch1 gene mRNA in testis tissue was higher than that of the control group at the same period in the middle and high dose groups at weeks 2,6,and 12 and the high dose group at weeks 4 and 8(P<0.05).,There is no interaction between exposure dose and exposure time.The expression level of Notch2 gene mRNA in testis tissues was higher than that of the control group at the middle,high-dose group at weeks 2,4,6,and 8 and the high-dose group at week 12(P<0.05),and at week 8 of the high-dose group Higher than the second week(P<0.05),there was no interaction effect between exposure dose and exposure time.6.WB results showed that the expression levels of Notch1 protein in testicular tissues of the low-dose,medium-dose group at week 2,and the medium-dose group at week 6,were higher in the test groups at weeks 4,8,and 12 than those in the control group(P<0.05),the expression level of Notch1 protein in week 12 and week 8 and 12 of the low-dose group was higher than that in week 2(P<0.05).There was an interactive effect between exposure dose and exposure time.The levels of Notch2 protein expression in testis tissues in the test groups at weeks 4,6,and 12 and the low-dose group at week 2 and the low-dose and medium-dose groups at week 8 were higher than those in the control group at the same period(P<0.05).The expression levels of Notch2 protein in the 8th and 12 th weeks of the group and the 4th and 12 th weeks of the high-dose group were higher than those in the 2nd week(P<0.05).There was an interactive effect between the exposure dose and the exposure time.Conclusion: Cigarette smoke exposure can cause testicular tissue damage,alter the activity of AKP,?-GT,?-GD,and G-6-PD,exposure dose and exposure time have interactive effects in the determination of ?-GT,?-GD,G-6-PD activity in rat testis;increase the expression of Notch1 and Notch2 mRNA and protein,exposure dose and exposure time have an interactive effect on the expression levels of Notch1 and Notch2 protein in rat testis,and cause testicular tissue damage. |
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