Mechanisms Of High Glucose And Fat Diet During Pregnancy On Vascular Dysfunction Of Thoracic Aorta In Fetal Rats

Objectives:Descendants born to mothers who have high glucose and high fat diet during pregnancy are more liable to cardiovascular diseases.But the exact mechanism remains unknown,and vascular function is essential for maintaining normal blood pressure.Therefore,this study mainly explores the effect and mechanisms of high glucose and high fat diet on the vascular function of thoracic aorta(TA)of fetal rats.Methods:Pregnant Sprague-Dawley rats were randomly divided into two groups.the control group(CON)and the high glucose and high fat group(HGF).with 30 rats in each group.From the first day to the twenty-first day of gestation,pregnant rats in the HGF group were fed diet made up of 20%glucose solution and 42%fat.Pregnant rats in the CON group were given standard water and feed.On the 21st day of pregnancy.after anesthesia of pentobarbital sodium(50mg/kg),two groups of pregnant rats were dissected to separate fetal rats and placentas.Then the number of male and female fetal rats per litter were counted separately,and the weight and diameter of the placenta,the length and weight of fetal rats,the weight of heart,kidney and liver were measured.The isolated thoracic aorta vessels of fetal rats were subjected to vascular function and molecular biological tests.The vascular tone detection system was used to detect the vasoconstriction response of the thoracic aorta rings of male and female fetal rats to Angiotensin Ⅱ(Ang Ⅱ).We investigated the mechanism of the high glucose and fat diet during pregnancy leading to vascular dysfunction of thoracic aortas in male and female fetal rats with the application of Angiotensin Ⅱ receptor related drugs[Angiotensin Ⅱtype 1 receptor(AT1R)inhibitor Losartan and Angiotensin Ⅱ type 2 receptor(AT2R)inhibitor PD123319],PKC pathway related drugs[Protein kinase C(PKC)pathway agonist 12,13-dibutanol(PDBu)and PKC pathway inhibitor GF109203X(GF)],Ca2+related drugs[L-type Ca2+ channels(LTCCs)agonist BayK8644,L-type Ca2+ channels inhibitor Nifedipine(NIFE)and endoplasmic reticulum inositol-1,4,5-triphosphate receptors(IP3Rs)inhibitor 2-Aminoethyl diphenylborinate(2APB)].Rho-assisted kinase(ROCK)inhibitor Y-27632 and oxidative stress pathway related drugs[Superoxide Dismutase(SOD)inhibitor Tempol.NADPH oxidase(NOX)inhibitor Apocynin and NADPH oxidase subtype NOX2 inhibitor Vas2870].The dihydroethidium(DHE)fluorescence probe method was used to determine the content of superoxide anion(O2-)in the thoracic aortas of male and female fetal rats.Using Real-Time quantitative polymerase chain reaction method(Real-Time PCR)and Western blot,the related gene was detected in molecular expression level:the immunofluorescence Colony Staining(IFC)method was used to further verify the expression level of related gene.Results:Compared with the CON group,the number of both male and female fetal rats per litter in the HGF group did not increase significantly,but the body length and weight of male and female rats in the HGF group increased.The placental weight and diameter of male and female fetal rats in the HGF group had no significant changes,but the weight of the liver was significantly decreased,and the weight of the heart and kidney was not different.In the vascular function test,compared with the CON group.the Ang Ⅱ-induced vasoconstriction response of the thoracic aortas of male and female fetal rats in the HGF group was significantly enhanced:After applying the cumulative concentrations of BayK8644 or PDBu.there was no difference in systolic response between the two groups.After incubation with NIFE.2APB,GF,or Y-27632,the AngⅡ-induced vasoconstriction response was partially attenuated between the two groups,but the Ang Ⅱ-induced vasoconstriction difference was not eliminated.After incubation of Tempol.Apocynin or Vas2870,the Ang Ⅱ-mediated vasoconstriction response between the two groups was inhibited,and the difference in Ang Ⅱ-induced vasoconstriction between the two groups was eliminated.The content of superoxide anion(O2-)in the thoracic aortas of male and female fetal rats in the HGF group was significantly higher than in the CON group;IFC,Western blot and Real-Time PCR showed that the expression level of NOX2 increased.Conclusions:High glucose and fat diets during pregnancy can enhance AngⅡ-mediated vasoconstriction response in the thoracic aorta of male and female fetal rats,which is related to the increase of superoxide anion(O2-)content caused by the up-regulation of NOX2 expression.