Effects Of Estrogen Levels On Renal Function And Vascular Systolic And Diastolic Factors In Renovascular Hypertension Rats

Objective:To investigate the effect of estrogen level on renal function and systolic and diastolic factors in normal blood pressure rats and 2K1C rats,and the effects on the mRNA and protein expression of renin-angiotensin system in the kidney of 2K1C rats.Methods:30 male rats and 75 female rats were taken.Renovascular hypertension was established in the surgery group by two kidney one clip operation through clipping right renal artery,at the same time thirty female SD rats had removed both ovaries,and an animal model of hypertension with low estrogen level was established.Fifteen female SD rats were excised with bilateral ovaries to establish a simple low estrogen model.The experiment was divided into 7 groups,namely male sham group?sham-M?,female sham group?sham-F?,castration-only group?OVX?,male surgery group?2K1C-M?,female surgery group?2K1C-F?,female surgical castration group?2K1C-OVX?,castration surgery supplemented estradiol group?2K1C-OVX-E2?.The 2K1C-OVX-E2 group was subcutaneously injected with 17?-estradiol?15?g/kg?daily after surgery.After 32 weeks,blood pressure was measured after anesthesia.Blood and kidney tissues were collected,and related indicators and mRNA and protein expression of RAS components were detected.Results:1.Estrogen has little effect on blood pressure.2.Effects of estrogen on renal function:BUN levels in the 2K1C-OVX-E2 group were higher than those in the2K1C-OVX group.3.Effects of estrogen on systolic and diastolic factors:Compared with the 2K1C-M group,the levels of 6-K-PGF_1ain the plasma and kidney were decreased in the 2K1C-F group.Compared with the 2K1C-F group,the levels of renal ET-1 and TXB2were reduced and the levels of plasma 6-K-PGF_1awere increased in the 2K1C-OVX group.Compared with the 2K1C-OVX group,the content of ET-1 in the kidney was increased in the 2K1C-OVX-E2 group.4.Effects of estrogen on oxidative stress:The MDA content in kidney of 2K1C-OVX-E2 group was higher than that of 2K1C-OVX group.5.Effects of estrogen on RAS:Compared with the 2K1C-M group,the Ang?1-7?content was reduced in the 2K1C-F group.The mRNA expressions of renin,ACE1,AT_1aR,and AT_1bR in the2K1C-F group were higher than that in the 2K1C-M and 2K1C-OVX groups.The mRNA expression of AT₂R was lower than that in 2K1C-M and 2K1C-OVX groups;the mRNA and protein expressions of ACE2 and MasR in 2K1C-F group were lower than those in2K1C-M and 2K1C-OVX groups.Conclusions:1)Estrogen may impair the renal function of renovascular hypertension rats by promoting 6-K-PGF_1a/TXB2 imbalance and activating the RAS system.2)Estrogen reduced the activity of Ang?1-7?-ACE2-MasR axis in renal tissue of 2K1C rats.