| ObjectiveTo observe the possible effects of high fructose intake during pregnancy on the bone development of offspring rats and preliminarily explore the possible mechanism.Method1.Animal grouping and intervention: Forty-eight pregnant Sprague Dawley rats were randomly divided into four groups according to body weight on embryonic day 0(ED 0)and given the same dose of distilled water(CON,n = 12),20 g/kg*d glucose(GLU,n =12),10 g/kg*d fructose(LFRU,n = 12)or 20 g/kg*d fructose(HFRU,n = 12)for 21 days during gestation.On ED 21,half of the dams were weighed,fasted overnight and anaesthetized.Blood was collected,and the fetal rats,liver,gastrocnemius and femur from each dam were removed and weighed.On ED 22-23,the other dams gave birth naturally and were provided distilled water during lactation.To standardize nutrition,each litter was adjusted to 8 pups(4 males and 4 females).Offsprings were weaned at 3 weeks of age and16 rats(8 males and 8 females)were randomly selected from each group and provided distilled water until 7 weeks of age.Offsprings at 7 weeks of age were fasted overnight and anaesthetized.Blood was collected and the liver,gastrocnemius,femur,and tibia from each rat were removed and weighed.2.The behavior of dams and offspring rats in each group were observed daily.The body weight,food intake of dams and offspring rats in each group were recorded weekly.3.Oral glucose tolerance test(OGTT)was performed on dams(ED 20)and offspring rats(7 weeks of age)to observe the blood glucose status and the area under the curve(AUC)was calculated.Serum insulin level was detected by enzyme linked immunosorbent assay(ELISA),and the insulin resistance index(HOMA-IR)was calculated.4.The serum fructose and uric acid levels of dams and offspring rats were detected by the kit.5.Quantum GX Micro-CT scanner was used for reconstruction measurement and quantitative analysis of the femoral microstructure of the offspring rats.6.ELISA was used to measure the level of N-terminal propeptide of type I procollagen,PINP)and C-telopeptide of type I collagen(CTX)of the offspring rats.7.Hematoxylin and eosin(H.E)staining and Tartrate resistant acid phosphatase(Trap)staining were used to observe the histopathological changes of bone in offspring rats.8.Western blot(WB)was used to determine the protein expression of osteoprotegerin(OPG)and receptor activator of nuclear factor-κB ligand(RANKL)in the femur of offspring rats.Result1.There was no significant differences in energy intake and body weight during pregnancy among the four groups(P > 0.05).Compared with the CON group and GLU group,the body weight of fetal rats at 21 days of pregnancy in the HFRU group was significantly decreased(P < 0.05).2.There was no significant difference in OGTT among the four groups of dams(P > 0.05).Compared with the CON group and GLU group,fasting serum insulin concentration and HOMA-IR of dams in the HFRU group were significantly increased(P < 0.05).3.Compared with the CON group,the serum fructose concentration of dams in the HFRU group was significantly increased(P < 0.05).And compared with the CON group and GLU group,serum uric acid concentration of dams in the HFRU and LFRU group was significantly increased(P < 0.05).4.Compared with the CON group and GLU group,the body weight of offspring male and female rats in the HFRU group was significantly decreased at the 6th and 5th week,respectively(P < 0.05).And compared with CON group,food intake and energy intake of offspring rats in the HFRU group were significantly decreased at the 4th,5th,6th and 7th weeks(P < 0.05).Compared with the CON and GLU group,gastrocnemius weight and femur weight of offspring rats in the HFRU group were significantly decreased(P < 0.05).5.There was no significant difference in the serum blood glucose concentration of offspring rats at 30 min,60 min and 120 min of OGTT(P > 0.05).Compared with the CON group,fasting blood glucose concentration of offspring rats in the HFRU and LFRU group was significantly increased(P < 0.05),and the AUC of offspring rats in the HFRU group was significantly increased(P < 0.05).Meanwhile,compared with the CON and GLU group,fasting serum insulin concentration and HOMA-IR of offspring rats in the HFRU group were significantly increased(P < 0.05).6.There was no significant difference in serum fructose among the four groups of offspring rats(P > 0.05).Compared with the CON and GLU group,the serum uric acid level of offspring rats in the HFRU group was significantly increased(P < 0.05).7.Compared with the CON and GLU group,bone mean density(BMD),cortex mean density(c BMD),and trabecular mean density(t BMD)of offspring rats in the HFRU group were significantly decreased(P < 0.05).In addition,compared with the CON group,total cross-sectional area inside the periosteal envelope(Tt.Ar),cortical bone area(Ct.Ar),medullary(or marrow)area(Ma.Ar),average cortical thickness(Ct.Th),periosteal perimeter(Ps.Pm),endpcortical perimeter(Ec.Pm),and polar moment inertia(Jo)of offspring rats in the HFRU group were decreased(P < 0.05).And compared with the CON group,trabecular number(Tb.N),bone surface density(BS/TV),trabecular thickness(Tb.Th),and connectivity density(Conn.D)were decreased in the HFRU group(P < 0.05),while the mean intercept length(MIL)was significantly increased(P < 0.05).8.Compared with the CON and GLU group,PINP and CTX levels in HFRU and LFRU group were significantly increased(P < 0.05).9.HE staining showed that the growth plate of the metaphysis was abnormal and that the chondrocyte proliferative zone was reduced of offspring rats in the HFRU group.Trap staining showed a large number of giant and multinucleated osteoclasts closely distributed and had irregular shapes.10.Compared with the CON group,the protein expression level of OPG and RANKL in femur of offspring rats in the HFRU group were significantly decreased(P < 0.05).Conclusion1.High fructose intake during pregnancy damaged the bone microstructure parameters of cortex and cancellous bone,inhibited the bone conversion process,and increased the number of osteoclasts in offspring rats.2.High fructose intake during pregnancy increased maternal and fetal uric acid levels,which have adverse effects on bone development.3.High fructose intake during pregnancy may affect bone formation and bone resorption processes,as well as bone growth and development,by inhibiting OPG/RANKL protein expression levels in offspring rats.4.Limit intake of excessive fructose-rich diet during pregnancy to avoid long-term adverse effects on offspring. |
