thromboxane-b2 and Menorrhagia

The gynecologic and obstetric implications of the smooth muscle-relaxing, antiaggregatory prostacyclin and its endogenous antagonist, thromboxane A2, are reviewed. In addition to the vascular wall and circulating platelets, which are primary sources for prostacyclin and thromboxane A2, respectively, reproductive tissues produce great amounts of these prostanoids, evidently for the regulation of the vascular tone and/or vascular platelet interaction. Several gynecologic and obstetric disorders are characterized by abnormalities in prostacyclin and/or thromboxane A2. In primary menorrhagia the uterine release of prostacyclin is increased, and consequently menstrual blood loss can be reduced with various prostaglandin synthesis inhibitors. Prostacyclin relaxes the nonpregnant myometrium in vitro and may also do so in vivo, although intravenous infusion of prostacyclin has no effect upon the uterine contractility in nonpregnant or pregnant subjects. Patients with pelvic endometriosis may have increased levels of prostacyclin and thromboxane A2 metabolites in the peritoneal fluid. The prostacyclin/thromboxane A2 balance shifts to thromboxane A2 dominance in patients with gynecologic cancer. During pregnancy the production of prostacyclin and thromboxane A2 increases in the mother and fetoplacental tissue. Preeclampsia and other chronic placental insufficiency syndromes are accompanied by prostacyclin deficiency in the mother and in fetomaternal tissues and by an overproduction of thromboxane A2, at least in the placenta. These changes may account for the vasoconstriction and platelet hyperactivity, which are pathognomonic for hypertensive pregnancies. By directing the prostacyclin/thromboxane A2 balance to prostacyclin dominance (by dietary manipulation, administration of prostacyclin and/or its analogues, drugs with prostacyclin-stimulating and/or thromboxane A2-inhibiting action), it may be possible to prevent and/or treat hypertensive pregnancy complications in the future.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Ascitic Fluid; Endometriosis; Epoprostenol; Estrogens; Female; Genital Diseases, Female; Genital Neoplasms, Female; Humans; Hypertension; Menorrhagia; Platelet Aggregation; Pre-Eclampsia; Pregnancy; Pregnancy Complications; Pregnancy Complications, Cardiovascular; Progestins; Thromboxane A2; Thromboxane B2; Thromboxanes; Uterine Contraction; Vasoconstriction

Topics: Dysmenorrhea; Endometriosis; Fatty Acids; Female; Genital Diseases, Female; Genital Neoplasms, Female; Humans; Menorrhagia; Prostaglandin Antagonists; Prostaglandins F; Prostanoic Acids; Thromboxane B2

Shen Qian Gujing Granule, a Chinese herbal preparation has shown its efficacy of 87.7% in treating menorrhagia. PGE2, PGE2 alpha, TXB2 and 6-Keto-PGF1 alpha levels were measured in the endometrium and menstrual blood of both normal menstrual women and patient with menorrhagia before and after the treatment. Local TXB2 values of endometrial and menstrual blood were significantly higher in menorrhagia patients than that in normal subjects (P < 0.05). And the local PGE2 values were higher in patients accompanied with Qi Deficiency (P < 0.05) and lower in patients without Qi Deficiency (P < 0.05). After the treatment, the local TXB2, PGE2 levels normalized. It suggests that Shen Qian Gujing Granule had a biphasic regulation on local PG values which yields good results for menorrhagia. Some mechanism were discussed.

Topics: Adult; Dinoprostone; Drugs, Chinese Herbal; Endometrium; Female; Humans; Menorrhagia; Thromboxane B2

The endometrial concentration of 6-keto-PGF1 alpha and TXB2 were measured by RIA in women with Tcu-IUD induced menorrhagia (MBL greater than 80 ml) and in levonorgestrel-IUD users with oligomenorrhea or amenorrhea. Non-IUD users with normal menses (MBL less than 80 ml) were chosen as control. It was found that the Tcu-IUD group showed a significantly higher 6-keto-PGF1 alpha concentration than the other two groups (P less than 0.01). Conversely, the TXB2 concentration of levonorgestrel-IUD group was significantly higher than that of the other groups (P less than 0.05). As a result, the 6-keto-PGF1 alpha/TXB2 ratio was much higher in Tcu-IUD group (P less than 0.01). Our results indicated that the unbalance of PGI2/TXA2 ratio may be the direct cause of the IUD-induced menorrhagia.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Endometrium; Epoprostenol; Female; Humans; Intrauterine Devices; Intrauterine Devices, Copper; Intrauterine Devices, Medicated; Levonorgestrel; Menorrhagia; Oligomenorrhea; Thromboxane B2

The role of the haemostatic system in relation to menstrual bleeding is poorly understood. Platelet retention to glass beads and plasma concentrations of 6-oxo-PGF1 alpha and thromboxane B2 were measured in uterine and peripheral venous blood obtained from 18 women undergoing abdominal hysterectomy. Concentrations of 6-oxo-PGF1 alpha were significantly (p less than 0.01) higher in uterine (1.4 +/- 0.3 ng/ml, mean +/- SEM) than in peripheral vein blood (0.2 +/- 0.1 ng/ml) as was the level of thromboxane B2 (0.5 +/- 0.1 and 0.2 +/- 0.1 ng/ml, respectively). Platelet retention in uterine vein blood (11 +/- 4%) was significantly lower than in peripheral blood (42 +/- 4%; p less than 0.01) and the degree of platelet retention correlated inversely with the plasma concentration of 6-oxo-PGF1 alpha (r -0.43; p less than 0.01). There was a significant rank correlation between time since menstruation and concentrations of 6-oxo-PGF1 alpha in uterine (tau + 0.69; p less than 0.001) and peripheral (tau + 0.56; p less than 0.05) vein blood. The results indicate that an increased local production of prostacyclin (PGI2) relative to thromboxane A2 at the time of menstruation could contribute to the mechanism of uterine bleeding.

Topics: Adult; Aged; Female; Humans; Menorrhagia; Menstruation; Middle Aged; Platelet Adhesiveness; Prostaglandins F; Thromboxane B2; Thromboxanes; Uterus; Veins