雌激素受体相关受体α过度表达对雌激素受体阴性的子宫内膜癌细胞增殖的影响

目的探讨雌激素受体相关受体α（ERRα）在雌激素受体（ER）阴性及阳性的子宫内膜癌细胞中的作用。方法 将真核表达质粒pSG—ERRα（0．5、1．0、1．5、2．5μg）瞬时转染子宫内膜癌细胞株HEC-1A（ER阴性）、HEC-1B（ER阴性）、Ishikawa（ER阳性）,采用定量RT-PCR技术和蛋白印迹法（westernblot）检测ERRα mRNA和蛋白的表达情况;采用流式细胞仪分析细胞周期,并计数细胞的增殖情况。结果 转染pSG—ERRα质粒后,HEC-1A、HEC-1B、Ishikawa细胞在mRNA和蛋白水平均能检测到ERRet的表达增加。HEC-1B、HEC-1A、Ishikawa细胞未转染时ERRα mRNA的表达水平分别为2104．2、2870．6、1476．8copies／ng,转染后3者ERRα mRNA的表达水平分别为9835．3、9644．4、8008．6copies／ng,分别与各自未转染的细胞比较,差异均有统计学意义（P值分别为0．004、0．002、0．002）。HEC-1A、HEC-1B、Ishikawa细胞未转染时ERRα蛋白的表达水平分别为0．823、0．192、0．673,转染后3者ERRα蛋白的表达水平分别为1．128、1．104、1．008,分别与各自未转染的细胞比较,差异均有统计学意义（P〈0．05）。随着转染pSG—ERRα质粒质量的增加,HEC-1A、HEC-1B细胞的S期和G2／M期细胞比例明显上升（P〈0．01）。HEC-1B、HEC-1A细胞转染0．5、1．0μg pSG-ERRα质粒后,细胞在转染后24—96h间生长速度显著加快（P〈0．05）。结论ERRα过度表达是ER阴性的子宫内膜癌细胞株HEC-1A、HEC-1B的一种细胞增殖机制。     

华蟾素对子宫内膜癌Ishikawa细胞RRM2表达的影响和意义

目的:探讨华蟾素对体外培养的子宫内膜癌Ishikawa细胞增殖、侵袭力及其对RRM2表达的影响和意义。方法:体外培养Ishikawa细胞,经不同浓度华蟾素干预后,用RT-PCR及Western blot分别检测RRM2在mRNA及蛋白水平上的表达,用MTT法检测处理前后细胞的增殖,transwell小室分析细胞体外的侵袭力。结果:华蟾素能显著减少RRM2在mRNA及蛋白水平的表达,有效地抑制Ishikawa细胞增殖,降低侵袭力,研究证实华蟾素终浓度3.0mg/ml是最佳抑制浓度,对照组Ishikawa细胞组则无上述效应。结论:华蟾素可明显降低Ishikawa细胞中RRM2表达,抑制细胞增殖,降低细胞侵袭力。     

CXCR7及其配体在子宫内膜癌中的表达与意义

目的:检测趋化因子受体CXCR7(chemokine receptor 7)及其配体在子宫内膜癌组织和子宫内膜癌细胞中的表达,并研究雌激素对该受体的调控作用。方法:首先通过RT-PCR分析20种趋化因子受体在子宫内膜癌细胞株Ishikawa(ERα阳性)和AN3CA(ERα阴性)的转录水平,筛选出子宫内膜癌细胞株高表达的趋化因子受体,以免疫细胞化学染色法测定该受体及其相应配体在子宫内膜癌组织和细胞中的表达,并用蛋白质印迹法观察雌激素对该受体蛋白水平表达的影响。结果:(1)CXCR7 mRNA在子宫内膜癌细胞株Ishikawa、AN3CA均呈高表达,免疫细胞化学示子宫内膜癌组织和Ishikawa、AN3CA细胞表达CXCR7及其配体SDF-1,不表达I-TAC;(2)在Ishikawa中,雌激素在一定浓度范围内上调细胞中CXCR7蛋白水平的表达,而在AN3CA中,雌激素对CXCR7蛋白并无明显的调节作用。结论:CXCR7/SDF-1高表达于子宫内膜癌组织和子宫内膜癌细胞中,且雌激素上调CXCR7的表达,表明CXCR7/SDF-1可能在子宫内膜癌中发挥调控作用。     

Gonadotropin-releasing hormone (GnRH)-I regulation of interleukin (IL)-1b and IL-1 receptor antagonist expression in cultured human endometrial stromal cells

Aim:  Human endometrium is an active site of cytokine production and action. Among these cytokines, the interleukin-1 (IL-1) system seems to be relevant to the embryonic implantation process. We have previously reported the production of GnRH-I by human blastocyst, as well as the presence of GnRH-I receptor in human endometrium. This suggests a close interaction between the immune and endocrine systems through these cytokine mediators in embryonic implantation.
Methods:  To test the relevance of this interaction during embryonic implantation, we investigated GnRH-I regulation of IL-1b and IL-1ra mRNA and protein expression in human endometrial stromal cells using quantitative competitive polymerase chain reaction and ELISA.
Results:  IL-1b mRNA and protein expression in cultured human endometrial stromal cells was significantly enhanced by GnRH-agonist in comparison to control groups. IL-1ra mRNA and protein was significantly decreased by GnRH-agonist in comparison to control groups. In contrast, the GnRH-antagonist ablated the regulatory effects of GnRH agonist in 1b and IL-1ra mRNA and protein levels in a dose-dependent manner.
Conclusions:  In conclusion, these results suggest a possible close interaction between the immune and endocrine systems in human embryonic implantation through the classical neuropeptide hormone GnRH and its receptor.     

EGFR过表达降低人子宫内膜癌细胞孕激素敏感性的研究

目的:检测表皮生长因子受体(EGFR)基因在子宫内膜癌孕激素敏感细胞株Ishikawa及孕激素不敏感细胞株KLE的表达,探讨EGFR基因过表达对人子宫内膜癌细胞孕激素敏感性的影响。方法:实时定量PCR法和蛋白印迹法检测Ishikawa和KLE细胞中EGFR及PR-BmRNA和蛋白的表达。将EGFR全长cDNA真核表达质粒在脂质体介导下转染至Ishikawa细胞,同时以转染空载体和未转染的Ishikawa细胞为对照,分别应用实时定量PCR检测各组细胞EGFR、PR-BmRNA表达的变化,应用蛋白印迹法检测各组细胞EGFR、PR-B蛋白表达的变化;CCK-8法观察转染EGFR基因后Ishikawa细胞对孕激素敏感性的变化。结果:(1)Ishikawa细胞中,EGFRmRNA和蛋白的表达明显低于KLE细胞(P<0.001),而PR-BmRNA和蛋白的表达则显著高于KLE细胞(P<0.001);(2)稳定转染EGFR基因后,Ishikawa细胞中EGFRmRNA和蛋白的表达水平明显高于转染空载体和未转染的Ishikawa细胞(P<0.001),而PR-BmRNA和蛋白的表达水平则显著降低;(3)10-8、10-7、10-6、10-5mol/L的MPA对未转染和转染空载体的Ishikawa细胞的抑制作用显著(P<0.05),但对稳定过表达EGFR的Ishikawa细胞无明显抑制作用(P>0.05)。结论:转染EGFR基因能有效提高Ishikawa细胞内EGFR基因的表达,但可下调PR-B基因的表达使Ishikawa细胞对MPA不敏感。     

The role of arginine vasopressin in human labour: functional studies, fetal production and localisation of V1a receptor mRNA

Objective To investigate labour-associated changes in: 1. the myometrial contractile response to arginine vasopressin compared with oxytocin in vitro 2. fetal production of arginine vasopressin and 3. myometrial vasopressin  V_1a  receptor mRNA.
Design The contractile response to vasopressin (compared with oxytocin) was investigated in paired myometrial strips in vitro . Blood was taken from the umbilical artery and vein at delivery and arginine vasopressin measured by radio-immunoassay.  V_1a  receptor mRNA was determined by in situ hybridisation.
Results Myometrium was more sensitive to arginine vasopressin than oxytocin (   P <0.05 for frequency, amplitude and activity integral in paired strips  ) after, but not before labour. There was a marked umbilical arteriovenous difference in arginine vasopressin concentration at delivery suggesting fetal production which was not influenced by labour. Myometrial vasopressin  V_1a  receptor mRNA was not increased after the onset of labour.
Conclusions The human uterus is extremely sensitive to arginine vasopressin in vitro . Arginine vasopressin is produced by the fetus but fetal formation is not increased during labour.     

雌激素和紫杉醇对子宫内膜癌Ishikawa细胞中Bub1 mRNA表达的影响

目的 探讨雌激素和紫杉醇对子宫内膜癌Ishikawa细胞中Bub1 mRNA表达的影响.方法 (1)Ishikawa细胞中加入10 nmol/L的17β雌二醇(17β-E2)作用24、48和72 h,采用活细胞计数(CCK-8)法检测其增殖活力[以吸光度(A)值表示],以17β-E2浓度0 nmol/L者为空白对照.(2)按如下方法处理Ishikawa细胞:①加入不同浓度(0.1、10、1000 nmol/L)的17β-E2作用不同时间(5、15、30 min及1、2、4、8、12、16、24、30 h);②经同步化处理(即先期予无血清培养基培养),然后加入不同浓度(10、100 nmol/L)的紫杉醇作用不同时间(8、24 h);③未经同步化处理,直接加入100 nmol/L的紫杉醇作用4、8、16、24、48 h;均以作用时间0 h者为空白对照.采用实时定量PCR技术检测经上述方法处理后的细胞中Bub1 mRNA的表达水平(设空白对照为1,以倍数表示Bub1 mRNA的表达水平).结果 (1)17β-E2作用后Ishikawa细胞的增殖活力随着作用时间(24、48和72 h)的延长逐渐增加,其A值分别为0.86±0.10、1.66 ±0.10、2.32±0.24,呈时间依赖性(P＜0.01).(2)不同浓度(0.1、10、1000 nmol/L)的17β-E2作用不同时间(5、15、30 min及1、2、4、8、12、16、24、30 h)后,Ishikawa细胞中Bub1 mRNA的表达水平(与空白对照比较)随着17β-E2浓度的升高呈下降趋势,而随着作用时间的延长无明显变化.当17β-E2浓度为10 nmol/L时,细胞中Bub1 mRNA的表达水平最低,与空白对照比较,差异则有统计学意义(P=0.020);而当浓度为0.1、1000 nmol/L时,与空白对照比较,差异则无统计学意义(P=0.746,P=0.197).经同步化处理的Ishikawa细胞,予10 nmol/L的紫杉醇作用8、24 h后,Ishikawa细胞中Bub1 mRNA的表达水平下降,分别为(0.403±0.008)、(0.775±0.144)倍,两者比较,差异无统计学意义(P=0.251);紫杉醇作用8 h时与空白对照比较,差异有统计学意义(P=0.009);而紫杉醇作用24 h时与空白对照比较,差异则无统计学意义(P=0.396).100nmol/L的紫杉醇作用8、24 h后,Ishikawa细胞中Bub1 mRNA的表达水平下降,分别为(0.697±0.017)、(0.850±0.004)倍,两者比较,差异无统计学意义(P=0.061);而分别与空白对照比较,差异则均有统计学意义(P=0.038,P=0.019).未经同步化处理的Ishikawa细胞,予100 nmol/L紫杉醇作用4、8、16、24、48 h后,细胞中Bub1 mRNA的表达水平呈上升趋势,分别为(1.127±0.105)、(1.614±0.154)、(2.092±0.179)、(1.381±0.061)、(1.519±0.182)倍,各时间点间比较,差异有统计学意义(P＜0.01),其中作用16 h时表达最强.结论 雌激素可降调Ishikawa细胞中Bub1 mRNA的表达;紫杉醇对先期无血清培养的Ishikawa细胞可下调其Bub1 mRNA的表达,而对正常培养的细胞则上调其Bub1 mRNA的表达,提示紫杉醇在不同条件下杀伤子宫内膜癌细胞的效力与Bub1mRNA的表达失调有关.     

雌激素及其阻滞剂对Ishikawa细胞中ETS-1和VEGF调控的研究

目的:探讨雌激素及其阻滞剂对子宫内膜癌细胞系Ishikawa细胞中转录因子ETS-1和血管内皮细胞生长因子(VEGF)表达的调控机制。方法:用RT-PCR法检测分别使用不同浓度雌激素、雌激素受体阻滞剂氟维司群处理后Ishikawa细胞中ETS-1基因表达水平的变化;用细胞爬片免疫组化法检测分别使用这两种不同浓度药物后Ishikawa细胞中ETS-1与VEGF表达的差别;采用ELISA法检测分别使用两种不同浓度的药物后Ishikawa细胞培养液中VEGF蛋白表达量的变化。结果:(1)随着雌激素浓度增加,ETS-1基因表达上调(FP=3.84,P<0.05);随着氟维司群浓度增加,ETS-1基因表达下调(FP=7.01,P<0.01);(2)随着雌激素浓度增加,ETS-1(FP=3.72,P<0.05)和VEGF(FP=3.68,P<0.05)蛋白质水平表达都增加;随着氟维司群浓度增加,ETS-1(FP=4.37,P<0.05)和VEGF(FP=4.09,P<0.05)蛋白质水平的表达都减少;(3)随着雌激素浓度增加,分泌型VEGF蛋白表达量上升(FP=3.91,P<0.05);随着氟维司群浓度增加,分泌型VEGF蛋白表达量下调(FP=7.34,P<0.01)。结论:雌激素可促进Ishikawa细胞中ETS-1和VEGF的表达,VEGF表达与ETS-1表达呈正相关。     

胰岛素对子宫内膜癌细胞增殖和凋亡的影响

目的 探讨胰岛素对子宫内膜癌细胞系Ishikawa3-H-12细胞增殖、凋亡和细胞周期的影响。方法 应用免疫细胞化学方法和RT-PCR技术检测Ishikawa3-H-12细胞胰岛素受体（INSR）蛋白和mRNA的表达。以不同浓度胰岛素作用Ishikawa3-H-12细胞不同时间,采用四甲基偶氮唑蓝比色法、流式细胞仪检测细胞增殖、凋亡和细胞周期。结果 （1）Ishikawa3-H-12细胞INSR蛋白呈棕黄色阳性表达,并可见INSR基因的表达。（2）胰岛素以浓度和时间依赖的方式促进子宫内膜癌细胞增殖,1×10^-4mol／L胰岛素作用48h时促增殖作用最显著,增殖率为（340．2±15．9）％,与对照细胞（以胰岛素浓度为0作为对照,为100％）比较,差异有统计学意义（P〈0．05）。（3）胰岛素以浓度和时间依赖的方式使Ishikawa3-H-12细胞中G0／G1期细胞比例减少,S期细胞比例增加,1×10^-4mol／L胰岛素作用72h时最显著,G0／G1期细胞比例为（27．7±2．5）％,S期细胞为（55．2±1．4）％,分别与对照细胞[分别为（67．6±1．5）％、（15．7±1．0）％]比较,差异均有统计学意义（P〈0．05）;胰岛素对G2／M期细胞无影响（P〉0．05）。（4）随着胰岛素浓度的增加,Ishikawa3-H-12细胞凋亡率逐渐下降。1×10^-4mol／L胰岛素作用最显著,作用24、48、72、96h时的细胞凋亡率分别为（1．76±0．16）％、（1．70±0．15）％、（1．56±0．20）％、（1．31±0．24）％,分别与对照细[分别为（9．81±0．61）％、（9．93±1．44）％、（9．10±0．66）％、（10．30±1．20）％]比较,差异均有统计学意义（P〈0．05）。结论 胰岛素对子宫内膜癌Ishikawa3-H-12细胞具有促进增殖、抑制凋亡的作用。     

三氧化二砷对卵巢癌细胞的生长及化疗敏感性的影响

目的:研究三氧化二砷(As2O3)对人卵巢癌COC1细胞顺铂(cDDP)化疗敏感性的影响,As2O3与cDDP联合作用的效应以及As2O3对COC1细胞的生长抑制效应及机制。方法:四甲基偶氮唑蓝(MTT)比色法检测不同浓度As2O3、cDDP作用72h对卵巢癌细胞生长的抑制作用,As2O3对顺铂化疗敏感性的影响及两药联合作用的效应。逆转录聚合酶链反应(RT-PCR)和免疫印迹技术(Western blot)分别检测PIK3CA mRNA和AKT、ERK、MMP-2蛋白表达的变化。结果:单独应用As2O3或cDDP和联合用药时卵巢癌COC1细胞生长均受到抑制,并呈浓度依赖关系,联合用药组抑制率明显高于单独用药组(P<0.05);0.08~0.15μmol/L As2O3无明显细胞毒性,不能提高COC1细胞对顺铂的敏感性。各浓度(1、3、8、16μmol/L)As2O3作用24h可以下调AKT、MMP-2蛋白水平(P<0.05),并呈浓度依赖效应,但对ERK蛋白的表达无显著影响。0.5、1、2、4μmol/L As2O3作用4h,PIK3CA mRNA表达分别降低45.03%、53.05%、61.67%和72.91%(P<0.05)。结论:As2O3抑制COC1细胞增殖具有浓度依赖性,与顺铂联用有相加效应,可能与As2O3下调PIK3CA mRNA、AKT、MMP-2蛋白水平等有关。     

下调microRNA-205表达对人子宫内膜癌Ishikawa细胞增殖和侵袭的作用

目的:探讨下调microRNA-205(miR-205)表达对人子宫内膜样腺癌细胞系Ishika-wa增殖和侵袭的作用及可能的机制。方法:将miR-205抑制剂(miR-205 inhibitor)瞬时转染Ishikawa细胞,下调miR-205的表达;应用实时荧光定量PCR方法(qRT-PCR)检测miR-205的表达;噻唑蓝(MTT)法检测细胞增殖能力;Transwell小室法检测细胞侵袭能力。qRT-PCR和Western blot分别检测miR-205的预测靶基因ESRRG mRNA和蛋白表达水平。应用双荧光素酶分析方法鉴定miR-205和ESRRG 3'UTR的表达调节关系。结果:miR-205在Ishikawa细胞中呈高表达;转染miR-205 inhibitor的Ishikawa细胞中,miR-205表达降低了86.9%,细胞增殖和侵袭能力下降,同时细胞ESRRG mRNA和蛋白表达升高;miR-205通过直接与ESRRG mR-NA 3'UTR结合负调节其表达。结论:下调miR-205表达可抑制Ishikawa细胞增殖、侵袭能力;miR-205的生物效应可能与调节潜在抑癌基因ESRRG有关。     

PTEN augments doxorubicin-induced apoptosis in PTEN-null Ishikawa cells

To investigate whether PTEN can augment doxorubicin-induced apoptosis in PTEN-null Ishikawa cells. We previously demonstrated that Ishikawa cells do not possess functional PTEN protein because of protein truncations. Clones expressing the steady-state level of the PTEN protein from PTEN-null Ishikawa cells have been established and were used in this study. Doxorubicin is a commonly used anticancer drug in endometrial carcinoma. The cytotoxic effect of doxorubicin was evaluated using the methyl thiazoleterazolium (MTT) assay. We used the Hoechst 33258 staining to confirm the induction of apoptosis. Immunoprecipitation and Western blot analysis were performed to evaluate the effects of doxorubicin on phosphorylation of Bcl-2 antagonist of cell death (Bad) and protein kinase B (Akt/PKB). Doxorubicin induced death of all cell lines in a dose-dependent manner, but the death was more significant in PTEN-expressing clones than in parent Ishikawa cells. A low concentration of doxorubicin (0.1 muM) did not affect apoptosis in PTEN-null Ishikawa cells, but it induced apoptosis in PTEN-expressing clones. A high concentration (1 microM) induced apoptosis in all cell lines, but the percentages of apoptotic cells were higher in PTEN-expressing clones than in parent Ishikawa cells. In the clones, phospho-Akt/PKB and phospho-Bad (Ser-136) were downregulated. Doxorubicin reduced the levels of phospho-Akt/PKB and phospho-Bad (Ser-136) in all the cell lines, but the reduction was most significant in the PTEN-expressing clones. Our present results indicate that PTEN transfection significantly enhances doxorubicin chemosensitivity through effective induction of apoptosis by downregulation of the PI3K/Akt/PKB signaling pathway in Ishikawa cells.     

沉默PI3K基因对E2刺激后子宫内膜癌细胞增殖和凋亡的影响

目的:探讨沉默PI3K基因对雌激素刺激下的子宫内膜癌细胞增殖、迁移、凋亡的影响。方法:培养子宫内膜癌Ishikawa细胞,构建LV-PI3K-RNAi慢病毒载体转染Ishikawa细胞。实验分组Control组未经任何处理的Ishikawa细胞;Ishikawa组经E₂刺激的Ishikawa细胞;NC组经E₂刺激并转染阴性对照慢病毒的Ishikawa细胞;PI3Ki组经E₂刺激并转染LV-PI3K-RNAi慢病毒的Ishikawa细胞。Real-time PCR、Western blot法检测各组VEGF、bFGF、PI3K mRNA及蛋白表达水平,MTT法、流式细胞仪分别检测细胞增殖能力及凋亡的情况。结果:与Ishikawa组、NC组比较,PI3Ki组的VEGF、bFGF、PI3K mRNA及蛋白表达水平明显降低,细胞增殖能力显著降低,凋亡率增高,差异均有统计学意义(P<0.05)。结论:PI3K基因低表达可干扰E₂在基因、蛋白水平激活Ishikawa细胞产生VEGF、bFGF,从而下调E₂对子宫内膜癌细胞增殖和抑制凋亡的影响。     

Oxytocin mRNA content in the endometrium of non-pregnant women

Objective   To study oxytocin mRNA in the human endometrium at different phases of the menstrual cycle.
Design   An exploratory study in non-pregnant women.
Setting   The Department of Obstetrics and Gynecology, Lund University Hospital, Sweden.
Participants   Thirty-three women of fertile age undergoing hysterectomy or endometrial curettage on routine benign gynaecologic indications.
Methods   Endometrial tissue was obtained throughout the menstrual cycle. The presence of oxytocin mRNA was investigated by in situ hybridisation and by real time PCR.
Main outcome measures   Oxytocin mRNA signalling intensity found by in situ hybridisation of tissue obtained at different times of the menstrual cycle. Relative amounts of oxytocin mRNA measured by real time PCR.
Results   The signal for oxytocin mRNA obtained by in situ hybridisation was more pronounced in glandular epithelial cells than in stromal cells. Furthermore, it was most marked around mid-cycle. The expression of oxytocin mRNA was confirmed by real time PCR.
Conclusions   The results indicate that oxytocin may be synthesised in the endometrium of non-pregnant women, particularly in the glandular epithelial cells. Hormone released from these sources may have a paracrine action on the uterus. Oxytocin mRNA expression seems to be ovarian hormone dependent with the highest concentration around mid-cycle.     

Melatonin as a new drug for improving oocyte quality

Background:  Although recent technical advances have benefited infertile couples, inadequate embryo development as a result of poor quality oocytes still contributes to infertility. The purpose of the present study was to evaluate melatonin as a drug for improving oocyte quality in such cases.
Methods:  Twenty-seven women from whom fewer than three fertilized embryos were grown and who failed to fall pregnant in previous treatment cycles were enrolled in the current prospective clinical study. Subjects took 1 mg or 3 mg tablets of melatonin orally at 22:00 h from the fifth day of the previous menstrual cycle to the day they were injected with human chorionic gonadotropin. The numbers of mature follicles, retrieved oocytes, degenerate oocytes, and fertilized embryos were compared to their previous data without melatonin (the control cycle).
Results:  Intrafollicular melatonin concentrations were significantly increased, and intrafollicular lipid peroxide concentrations showed a tendency towards lower levels in the 3 mg melatonin treatment cycles compared with the control cycles. The number of degenerate oocytes was significantly reduced, and the number of fertilized embryos showed a tendency towards an increase in the 3 mg cycle compared to the control cycle. Three women succeeded in falling pregnant.
Conclusion:  Melatonin is likely to become the drug of choice for improving oocyte quality in women who cannot fall pregnant because of poor quality oocytes. (Reprod Med Biol 2003; 2 : 139–144)     

Erythromycin inhibits prostaglandin F2alpha-induced contractions of myometrium isolated from non-pregnant rats

Objective The aim of this study was to investigate the effects of erythromycin on prostaglandin F_2α (PGF_2α)-induced contractions of isolated myometrial strips from non-pregnant rats.
Design In vitro pharmacological study.
Setting Firat University Faculty of Medicine.
Sample Myometrium samples were taken from 55 adult Wistar rats.
Methods Myometrial strips were isolated from mature, non-pregnant Wistar rats. Isometric contractions of these strips were induced with 1 μM PGF_2α. Effects of 0.01, 0.1, 0.2, 0.5 and 1 mM erythromycin on the frequency and amplitude of these PGF_2α-induced contractions were recorded.
Main outcome measures The inhibition of prostaglandin F_2α-induced contractions in vitro .
Results Application of 0.01 mM erythromycin had no effect on either amplitude or frequency of contractions. However, 0.1, 0.2, 0.5 and 1 mM erythromycin decreased the frequency and amplitude of PGF_2α-induced contractions. The inhibitory effect of erythromycin on amplitude was 27%, 38%, 54% and 83% (   P < 0.05  ), and that on frequency was 10%, 16%, 32% and 61% (   P < 0.05  ) at 0.1, 0.2, 0.5 and 1 mM concentrations, respectively.
Conclusion The results of this study demonstrate that erythromycin inhibits PGF_2α-induced contractions in rat myometrium. Because PGF_2α-induced contractions have been suggested to be involved in the pathogenesis of primary dysmenorrhoea, effects of erythromycin in this clinical entity may present a new approach for the treatment.