Boquet M, Cebral E, Motta A, Berón de Astrada M, Gimeno M A
Centro de Estudios Farmacológicos y Botánicos, Consejo Nacional de Investigaciones Cientificas y Técnicas, Buenos Aires, Argentina.
Prostaglandins Leukot Essent Fatty Acids. 1998 Sep;59(3):163-7. doi: 10.1016/s0952-3278(98)90057-6.
Despite the evidence for a functional role of nitric oxide (NO) in the regulation of uterine contractility in several species, there is little information about the effects of this gas on the mouse uterus. The aims of this study were to investigate if the NO relaxation pathway is present in mouse pregnant uterus and the relationship with the uterotonic prostaglandins (PGs E and F2alpha) production. We evaluated the effect of the treatment with a competitive nitric oxide synthase (NOs) inhibitor: N(G)-monomethyl-L-arginine on the spontaneous contractile activity and prostaglandin production on two different days of pregnancy: second day of pregnancy (preimplantation stage) and on the afternoon of the fifth day of pregnancy (postimplantation stage). We found that only on the fifth day of pregnancy did the inhibitor induce a highly significant isometric developed tension (IDT) and that this effect was maintained throughout the experiment. In order to evaluate if the generation of NO was also different between the two days of pregnancy, NOs activity was measured. Total NOs activity was significantly elevated during the postimplantation stage. We studied the interaction between the NO and cyclooxygenase (COX) pathways on the fifth day of pregnancy, and the data show no stimulation of PGs production by endogenous NO. In summary, we found that NO participates in the control of uterine contractility on the fifth day (a postimplantation stage) and that in this condition the NO was not able to elicit an increase in PGs production.
尽管有证据表明一氧化氮（NO）在多种物种子宫收缩调节中发挥功能性作用，但关于这种气体对小鼠子宫的影响却知之甚少。本研究的目的是调查小鼠妊娠子宫中是否存在NO舒张途径以及与子宫收缩性前列腺素（PGs E和F2α）产生的关系。我们评估了用竞争性一氧化氮合酶（NOs）抑制剂：N(G)-单甲基-L-精氨酸处理对妊娠两个不同阶段自发收缩活性和前列腺素产生的影响：妊娠第二天（植入前阶段）和妊娠第五天下午（植入后阶段）。我们发现仅在妊娠第五天抑制剂诱导了高度显著的等长收缩张力（IDT），并且这种效应在整个实验过程中持续存在。为了评估妊娠两天之间NO的产生是否也不同，我们测量了NOs活性。在植入后阶段总NOs活性显著升高。我们研究了妊娠第五天NO与环氧化酶（COX）途径之间的相互作用，数据显示内源性NO未刺激PGs的产生。总之，我们发现NO在妊娠第五天（植入后阶段）参与子宫收缩的控制，并且在这种情况下NO不能引起PGs产生增加。
