Viggiano M, Franchi A M, Dveksler G, Gimeno M F, Gimeno A L
(CEFAPRIN), Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina, Buenos Aires.
Prostaglandins Leukot Med. 1987 Aug;28(3):285-302. doi: 10.1016/0262-1746(87)90118-1.
Cumulative dose-response curves for histamine induced responses in mesometrial (ME) and antimesometrial (AME) regions of uterine horns isolated from rats at 7th, 16th and 22nd days of pregnancy, were constructed. Histamine inhibited, in dose-related fashion, the isometric developed tension in ME and AME strips obtained at the 7th day of pregnancy, an action antagonized by cimetidine (10(-4)-10(-5) M). On the contrary, at the 16th and 22nd days, histamine (10(-5)-10(-3) M), stimulated spontaneous contractions in the ME region but had no effect in the AME segment. Although histamine and SKF-71481-A2,aH1-receptor agonist, both at 10(-4) M, enhanced similarly ME inotropism at the 16th and at 22nd days of pregnancy, the positive contractile action of histamine was greater at the 16th than at the 22nd day. Moreover, cumulative dose-response curves for histamine and SKF-71481-A2 in the ME region of uteri isolated at the 16th day of gestation, showed that both agonists have approximately the same inotropic potency and efficacy. On the other hand, pyrilamine (at 10(-4) M, but not at 10(-5) M aH1-receptor antagonist, shifted to the right the dose-response curve for histamine in ME strips from uteri at the 16th day of pregnancy and attenuated significantly, the magnitude of the positive inotropism evoked by the amine. Similar findings were observed in the presence of chlorpheniramine (at 10(-6) M), another H1-receptor blocker. In addition, the positive uterine inotropism evoked by histamine in the ME region of preparations isolated at the 16th day of pregnancy, was significantly reduced by an antagonist of phospholipase A2 (mepacrine, 10(-4) M) as well as by acetylsalicylic acid (ASA at 10(-4) M), an inhibitor of cyclooxygenase. Results also indicate that the excitatory uterine inotropism elicited by the agonistic amine in ME strips isolated from rats at the 16th day of pregnancy, was coincident with an enhanced release of prostaglandins (PGs) E2 and F2 alpha, but not of PGE1 and that both augmenting actions of histamine were antagonized by histamine H1 receptor-blockers, namely pyrilamine (mepyramine or chlorpheniramine. Results suggest that histamine at early pregnancy diminished myometrial inotropism via its interaction with H2-receptors, whereas from mid pregnancy up to the moment of parturition it evokes contractile stimulation, most likely due to the activation of H1-receptor located at the mesometrial region of rat uterine horns.(ABSTRACT TRUNCATED AT 400 WORDS)
构建了从妊娠第7天、第16天和第22天的大鼠分离出的子宫角的子宫系膜（ME）和子宫系膜对侧（AME）区域中组胺诱导反应的累积剂量-反应曲线。组胺以剂量相关的方式抑制妊娠第7天获得的ME和AME条带中的等长收缩张力，西咪替丁（10⁻⁴ - 10⁻⁵ M）可拮抗该作用。相反，在第16天和第22天，组胺（10⁻⁵ - 10⁻³ M）刺激ME区域的自发收缩，但对AME段无影响。尽管组胺和SKF - 71481 - A2（一种H1受体激动剂）在10⁻⁴ M时，在妊娠第16天和第22天同样增强了ME的收缩性，但组胺的正性收缩作用在第16天比第22天更大。此外，在妊娠第16天分离的子宫的ME区域中组胺和SKF - 71481 - A2的累积剂量-反应曲线表明，两种激动剂具有大致相同的收缩效力和效能。另一方面，吡苄明（在10⁻⁴ M，但不在10⁻⁵ M，一种H1受体拮抗剂）使妊娠第16天子宫的ME条带中组胺的剂量-反应曲线右移，并显著减弱了胺引起的正性收缩力的幅度。在存在另一种H1受体阻滞剂氯苯那敏（10⁻⁶ M）时观察到类似的结果。此外，妊娠第16天分离的制剂的ME区域中组胺引起的子宫正性收缩力，被磷脂酶A2拮抗剂（米帕林，10⁻⁴ M）以及环氧化酶抑制剂乙酰水杨酸（ASA，10⁻⁴ M）显著降低。结果还表明，妊娠第16天从大鼠分离的ME条带中激动性胺引起的兴奋性子宫收缩力，与前列腺素（PGs）E2和F2α的释放增加一致，但与PGE1的释放无关，并且组胺的两种增强作用均被组胺H1受体阻滞剂拮抗，即吡苄明（美吡拉敏或氯苯那敏）。结果表明，妊娠早期组胺通过与H2受体相互作用降低子宫肌层收缩性，而从妊娠中期到分娩时，它引起收缩刺激，最可能是由于位于大鼠子宫角子宫系膜区域的H1受体的激活。（摘要截断于400字）
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