长效醋酸甲羟孕酮对子宫内膜异位症大鼠疗效及副作用探讨

The effect of DMPA in the rat model of endometriosis

目的 建立实验用SD大鼠子宫内膜异位症模型,观察长效醋酸甲羟孕酮(depot medroxy progesterone acetate,DMPA)对子宫内膜异位症(endometriosis,EMs)大鼠的疗效,评估其对大鼠骨密度及骨代谢生化指标的影响,为指导临床用药提供参考.方法 建立大鼠EMs模型,将40只大鼠随机均分为4组,每组10只,A组为灭菌水对照组(灭菌水0.05 ml/kg×6.25),B组为DMPA低剂量组(0.025 ml/kg×6.25),C组为DMPA中剂量组(0.05 ml/kg×6.25),D组为DMPA高剂量组(0.1 ml/kg×6.25),观察治疗前后大鼠异位囊肿体积的变化以及大鼠股骨、腰椎及全身骨密度和血清骨生化代谢指标的改变.结果 ①异位囊肿体积变化:治疗后,各组EMs大鼠的异位囊肿体积较治疗前明显缩小,而A组异位囊肿体积无明显改变(tA=0.39,PA=0.71,tB=65.35,PB<0.05,tC=37.61,PC<0.05,tD=50.43,PD<0.05);②骨密度:仅D组大鼠腰椎骨密度(bone mineral density,BMD)较治疗前下降(PD<0.05);③血清骨代谢生化指标:A、B组Ⅰ 型胶原交联C-末端肽(C-terminal telopeptide of typeⅠcollagen,CTX-Ⅰ)、Ⅰ 型胶原交联N-末端肽(N-terminal telopeptide of typeⅠcollagen,NTX-Ⅰ)、Ⅰ 型前胶原氨基端前肽(procollagen typeⅠN-terminal peopeptide,PINP)、骨碱性磷酸酶(bone-alkaline phosphatase,BALP)较治疗前均无明显变化;C、D组骨吸收指标(CTX-Ⅰ、NTX-Ⅰ)较治疗前明显升高,骨形成标志物(PINP、BALP)较治疗前下降,差异均有统计学意义(tA-NTX-Ⅰ=-1.26,PA-NTX-Ⅰ=0.25;tB-NTX-Ⅰ=-1.96,PB-NTX-Ⅰ=0.091;tC-NTX-Ⅰ=-23.74,PC-NTX-Ⅰ<0.05;tD-NTX-Ⅰ=-18.49,PD-NTX-Ⅰ<0.05;tA-CTX-Ⅰ=-0.20,PA-CTX-Ⅰ=0.85;tB-CTX-Ⅰ=0.24,PB-CTX-Ⅰ=0.82;tC-CTX-Ⅰ=-4.05,PC-CTX-Ⅰ<0.05;tD-CTX-Ⅰ=-5.01,PD-CTX-Ⅰ<0.05);C、D组血清E2与骨代谢生化指标的相关性分析示:NTX-Ⅰ、CTX-Ⅰ 与血清E2浓度呈负相关(r=-0.51,-0.72;P<0.05);而PINP、BALP的表达与血清E2浓度呈正相关(r=0.69,0.63;P<0.05).结论 DMPA可抑制EMs大鼠异位内膜生长,使其呈增殖抑制或萎缩性改变对异位囊肿有一定的缩复作用;DMPA对EMs大鼠骨骼影响与血清E2低表达密切相关,血清E2对骨密度的影响可能存在"浓度阈值窗"效应,只有当中、高剂量DMPA导致血清E2浓度低于该阈值窗下限时,才会引起骨形成活性减弱,骨吸收活性增强,骨转换率增加;且DMPA使用剂量越大,血清E2浓度越低,骨转换率越高,骨量流失越快,BMD出现下降的时间越早.

Objective To establish a SD rat model of endometriosis and evaluate the effect of DMPA on it by assessing the expression of bone mineral density(BMD)and bone biochemical metabolic markers.Methods Forty rats were randomized into group A,B,C and D with 10 rats each to establish a rat model of endometriosis.Rats in group A(control group)were injected with sterile water(0.05ml/kg×6.25).DMPA was intramuscularly injected(every five days,six times in total)into the left thigh of the rats in group B,C and D at doses of 0.025 ml/kg×6.25,0.05 ml/kg×6.25 and 0.1 ml/kg×6.25,respectively.Finally,endometrial cysts,serum estradiol levels,peritoneal fluid levels of IL-6/TNF-α,BMD(lumbar spine、femur、total body)and bone biochemical markers(CTX-I,NTX-I,PINP,BALP)before and after treatment of DMPA were evaluated.Results Serum estradiol level in group B,C and D were significantly lower than that in group A after DMPA treatment(P<0.05).The endometrial cysts in group B,C and D reduced significantly after DMPA treatment(P<0.05)while no difference was found in group A.Only lumbar spine BMD in group D reduced slightly after DMPA treatment(P<0.05).No significant difference was found in serum levels of biochemical markers(CTX-I,NTX-I,PINP and BALP)in group A and B after treatment(P>0.05).While in group C and D,marks of bone resorption(NTX-I/CTX-I)were increased along with a decrease of bone formation(PINP/BALP)(P<0.05).In addition,markers of bone resorption(NTX-I/CTX-I)in group C and D were negatively correlated with serum estradiol levels(r=-0.51,-0.72;P<0.05)and there was a positive correlation between PINP/BALP and estradiol(r=0.69,0.63;P<0.05).Conclusion DMPA could significantly inhibit the growth of ectopic endometrium and could reduce levels of IL-6/TNF-αin peritoneal fluid by altering peritoneal environment and attenuating inflammation.The bone effects of DMPA may be correlated with low estradiol.There may be a“threshold effect”in the correlation,which means that increased bone resorption and decreased bone formation occur when serum estradiol levels are lower than“threshold”values caused by moderate or high doses of DMPA.Moreover,the lower serum estradiol is,the much earlier the decrease occurs in BMD.