Effect Of Maternal Obesity On Germ Cells Of Male Offspring Rats

Objective In recent years,studies have shown that maternal obesity could not only damage themselves,but also affect the health of their offspring.In order to investigate the effect of maternal obesity on the adult germ cells of male offspring,a rat model of maternal obesity induced by high fat diet was established by the author to observe the effect,and the author also went further for the study related to the susceptibility of male offspring to metabolic diseases induced by high fat diet again in their adulthood.Methods Firstly,25 Wistar male rats are fed in single-cages for 2 days at the age of 4 weeks and then induced by high-fat diet for two weeks.According to the order of the rats weight gain,the middle I/3 is taken as the male control group(F0 CN,9 rats),which would continued to be fed with basic diet for 10 weeks.Secondly,80 Wistar female rats are fed in single-cages for 2 days at the age of 7 weeks and then induced by high-fat diet for two weeks.According to the the rats’weight gain,top 1/3 is randomly selected as the maternal obesity group(F0 HFD,10 rats),which continued to be fed with high fat diet,middle 1/3 rats are selected as the maternal control group(F0 CON,8 rats),which changed to basic diet for 6 weeks.Thirdly,make the F0 rats mate together after modeling at the ratio of 2:1.Check the female rats’ vaginal plug,confirm the pregnant ones and feed them individually until delivery.Finally,at the end of lactation,20 male offspring born from the maternal obesity(F0 HFD)group is randomly selected as the research objects of F1 maternal obesity experimental group(CH group),and 20 male offspring born from the maternal control(F0 CON)group is selected as F1 control group(CC group).These offspring would be fed with basic diet for 12 weeks,and then 10 offspring rats in each group would be put to death randomly,and the rest are induced by high fat diet for 4 weeks and put to death afterwards.All the serum and organ tissues of the 40 sample rats would be collected and checked,including serum glucose(GLU),insulin(INS),total cholesterol(CHO),triglyceride(TG),high-density lipoprotein(HDL-C),low-density lipoprotein(LDL-C).Sperm motility,reproductive hormone,oxidative damage,mitochondrial membrane potential(MMP),mitochondrial respiratory chain complex enzyme Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ and succinate dehydrogenase(SDH)would be detected.And also the morphological changes of testicular tissue under light microscope and transmission electron microscope would be observed.Results Compared with the control group,the food intake and body weight of the offspring in the experimental group had increased obviously,among them,the food intake had significantly different at week5,week6 and Week 11,the body weight of the rats had been strong different at the age of week4,Week10 and week12,the organ coefficient of testis had significantly reduced,the fat around the omentum majus,the CHO and HDLC had increased,the GIU and INS had changed a little;the reproductive hormones retinal ketone(T)and luteinizing hormone(LH)of testis tissue had obviously increased,with the and estrogen(E2)reduced.Under the light microscope,the proportion of spermatogenic epithelial cells in the progeny of the experimental group had reduced,and the differentiation process had slowed down,but no obvious difference in other structure;under transmission electron microscope,it had showed significant cell cavitation in Sertoli cells,spermatocytes,spermatogonia and mitochondria.Compared with the control group,the weight of week1,week2,week3 and week4 in the experimental group had increased significantly,with the increased organ coefficient especially the testis and epididymis;the reproductive hormone T and LH,ROS had increased obviously,with the mitochondrial respiratory chain complex Ⅲ decreased,and sperm mitochondrial respiratory chain complex Ⅱ had grew.Under the light microscope,the number of spermatogenic epithelium cells in the experimental group had decreased conspicuous,the process of cell differentiation had slowed down,the basement membrane space had became larger,which made the boundary inconspicuous;under the transmission electron microscope,the cytoplasm of Sertoli cells in testis had been loose,the cavitation of spermatocytes,spermatogonia and Sertoli cells had been serious,the perinuclear space had obviously expanded,the cell membrane had collapsed,the cell nuclear membrane had partially dissolved,and the mitochondria had been empty,and the endoplasmic reticulum had expanded slightly.Conclusion To conclude,obesity could not only affects the body weight,body fat and blood lipid on male offspring,but also reduces the homeostasis of reproductive hormones,made offsprings germ cell damage.When maternally obese offspring are induced by a high-fat diet again,the male offspring homeostasis of reproductive hormones had reduced,increases the production of oxygen free radicals,reduces the activity of mitochondrial enzymes,germ cell damage is more likely to occur.It shows that the impact of dietary environment on germ cells is greater than genetic damage.