Krister Gréen

Endogenous levels of prostaglandin F2α and its main metabolites in plasma and endometrium of normal and dysmenorrheic women

The concentrations of prostaglandin F2alpha 15-keto-13, 14-dihydro-PGF2alpha, and 13,14-dihydro-PGF2alpha were determined in plasma and in endometrial specimens taken from both dysmenorrheic and normal women at the time of their menstruation. The estimations were carried out by means of the gas chromatography-mass spectrometry method. The plasma levels of 15-keto-13,14-dihydro-PGF2alpha in dysmenorrheic women ranged between 32 and 105 pg. per milliliter, which are significantly higher than the corresponding levels in eumenorrheic women, 20 to 33 pg. per milliliter. On the first day of menstrual bleeding the concentration of PGF2alpha in the endometrium was approximately 4 times higher (300 to 2,600 pg. per milligram) in cases of dysmenorrhea than in normal subjects. Treatment with either oral contraceptives or prostaglandin synthetase inhibitors lowered the concentrations significantly and the majority of patients became symptom free.

The role of prostaglandin F2α in human parturition

Abstract The finding that exogenous prostaglandins have a potent and specific stimulatory action on uterine contractility in the human female as well as data suggesting increased concentrations of endogenous prostaglandins in amniotic fluid and blood serum during labor indicate that these compounds may play a role in human parturition. However, earlier results on blood levels of prostaglandin F 2α (PGF 2α ) remain controversial because of the possible formation of PGF 2α by platelets and blood cells during isolation of the plasma or serum. It seems that measurement of the PGF 2α metabolite 15-keto-13, 14-dihydro-PGF 2α by a gas chromatographic-mass spectrometric technique offers a more reliable method for monitoring PGF 2α biosynthesis. During the last month preceding labor, the concentration of 15-keto-13, 14-dihydro-PGF 2α increased slightly. During active labor the plasma level of the metabolite increased ten- to thirtyfold. One hour after delivery the concentration had decreased by 20 to 75 per cent. The presented data support the view that endogenously produced PGF 2α results in increased uterine activity during the last month of pregnancy and during labor.

Methods for quantitative analysis of PGF2α, PGE2, 9α,11α-dihydroxy-15-keto-prost-5-enoic acid and 9α,11α,15-trihydroxy-prost-5-enoic acid from body fluids using deuterated carriers and gas chromatography-mass spectrometry

Abstract The preparation of (3,3,4,4-D 4 )-PGE 2 , (3,3,4,4-D 4 )-PGF 2α , (3,3,4,4-D 4 )-9α,11α-dihydroxy-15-ketoprost-5-enoic acid and (3,3,4,4-D 4 )-9α,11α,15-trihydroxyprost-5-enoic acid is described. These compounds have been used for quantitative determination of corresponding nondeuterated prostaglandins by gas-liquid chromatography-mass spectrometry. The method is based on addition of a known amount of carrier to the sample and after purification and derivatization the ratio between the protium and deuterium form is measured in the mass spectrometer. Ions originating in deuterated and nondeuterated molecules are focused one at a time on the electron multiplier using an accelerating voltage alternator. With this technique 400 pg of PGF 2α can be determined with a precision of ±3.7% (SD). The recoveries from plasma samples, containing 1–2.5 ng/ml of any of the compounds, is about 100±10%.

INCREASED PLASMA LEVELS OF 15-KETO- 13,14-DIHYDRO-PROSTAGLANDIN F2α AFTER ALLERGEN-PROVOKED ASTHMA IN MAN

Abstract Specific allergens were administered as aerosols to five patients with type-I bronchial asthma until symptoms and signs of an asthmatic attack were provoked. Before and after provocation peripheral venous blood was sampled and analysed for 15-keto-13,14-dihydro-prostaglandin F 2α using combined gas-chromatography/mass spectrometry. The allergen-provoked asthmatic attacks were associated with an up to eightfold increase in 15-keto-13,14-dihydro-P.G.F 2α , the main metabolite of P.G.F 2a in plasma. The increase in P.G.F2a-metabolite, which could be demonstrated within a few minutes after starting the provocation, seemed to be correlated to the severity of the attack. These findings are compatible with and add more weight to the consideration that P.G.F 2a plays a significant role in the pathogenesis of asthma.

Prostaglandins, indomethacin and dysmenorrhea

Uterine contractility was recorded during the period of menstruation in six dysmenorrheic women. A variable high tonus was observed in each case. Uterine recordings were repeated during the subsequent menstruation following pre-treatment with indomethacin at an oral dose of 75 mg or 200 mg per day beginning one day before the expected onset of menstruation. A lower uterine tonus was found in all indomethacin-treated cycles. Complete alleviation of spasmodic pain was obtained in the six subjects. The endogenous concentration of 15-keto-13, 14-dihydro PGF2alpha was determined by the gas chromatography-mass spectrometry method and observed to be relatively high in women with dysmenorrhea.

Development of a GC-MS method for quantitation of 2,3-dinor-6-keto-PGF1∝ and determination of the urinary excretion rates in healthy humans under normal conditions and following drugs

Tetradeuterated 2,3-dinor-6-keto-PGF1 alpha was used as internal standard in the development of a method for quantitation of 2,3-dinor-6-keto-PGF1 alpha in human urine based on gas chromatography - mass spectrometry. The urinary excretion rates of 2,3-dinor-6-keto-PGF1 alpha in twenty normal healthy males and females were 9.7 +/- 4.6 and 8.8 +/- 8.5 (mean +/- SD) ng/h respectively. A considerable inter- and intra-individual variation was found under normal conditions. It was also found that the urinary excretion of 2,3-dinor-6-keto-PGF1 alpha was increased about fivefold during and shortly after 30 min of strenuous jogging. Any data about the effect of nonsteroidal antiinflammatory drugs on the excretion rate of 2,3-dinor-6-keto-PGF1 alpha are difficult to interpret when considering the above findings. However, oral administration of 500 mg of aspirin did not seem to reduce the excretion rate of 2,3-dinor-6-keto-PGF1 alpha.

Urinary excretion of 2,3-dinor-thromboxane B2 in man under normal conditions, following drugs and during some pathological conditions

Quantitation of 2,3-dinor-thromboxane B2 (2,3-dinor-TxB2) was performed by gas chromatography-mass spectrometry. Under normal conditions the urinary excretion of 2,3-dinor-TxB2 was relatively constant in the same individual from day to day but during a 24-hour period a somewhat higher excretion rate was found during the first few hours after awakening. A pronounced reduction of the urinary excretion of 2,3-dinor-TxB2 was found after oral administration of 500 mg of aspirin or 50 mg of indomethacin, while 500 mg of paracetamol did not affect the urinary excretion. Increased excretion of 2,3-dinor-TxB2 was found in normal pregnancies and in diseases such as diabetes mellitus and homocysteinuria in comparison to the urinary excretion in normal healthy subjects. We also report one case, where the urinary excretion of 2,3-dinor-TxB2 was increased for a short period following the first symptoms of a myocardial infarction and those data indicate that thromboxane A2 (TxA2) may be of pathophysiological importance in human myocardial infarction. The results strongly indicate that measurements of the urinary excretion of 2,3-dinor-TxB2 should be meaningful as a tool for investigation of the involvement of thromboxane in various pathophysiological processes in vivo in man.

Premature labor and indomethacin

Women in the 29th - 32nd week of gestation were admitted to hospital following the onset of premature labor contractions. After treatment with bed rest and beta-stimulating drugs, those patients with persistent uterine contractions were treated with oral indomethacin (25 mg every 6 hours for 5 days). The effect of indomethacin therapy was monitored by serial external tocometry recordings. This treatment schedule with indomethacin was repeated on several occasions at intervals of 5 to 10 days. Using a standardized technique, uterine contractility was monitored every second or third day throughout the entire treatment period. In this way, the frequency of contractions was evaluated in the presence or absence of indomethacin therapy. Following indomethacin treatment, there was a significant decrease in the frequency of contractions in all cases and a complete arrest of contractions occurred in some women. An increased frequency of contractions was observed during those times that the patient did not receive indomethacin. The plasms concentration of 15-keto-13, 14-dihydro-PGF2alpha, the major serum metabolite of PGF2alpha, was determined by the gas chromatography - mass spectrometry method before and after indomethacin in a limited number of cases. At the doses given for the duration of therapy used, no untoward effects could be detected in either the mother or the infant. These results indicate that indomethacin is a potent and useful drug in the treatment of premature labor.

In vivo production of prostacyclin and thromboxane in patients with acute myocardial infarction.

The in vivo production of prostacyclin and thromboxane was monitored by measuring their major urinary metabolites 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin F1 alpha in ten patients with acute myocardial infarction, five on standard treatment and five receiving prostacyclin infusion. During acute myocardial infarction excretion of 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-prostaglandin F1 alpha, measured by a gas chromatography-mass spectrometry method with deuterated internal standards, was significantly increased. This indicates that thromboxane and prostacyclin synthesis are increased during the development of acute myocardial infarction. The excretion data for 2,3-dinor-thromboxane B2 showed that after administration of aspirin there was less pronounced and more variable inhibition than expected. Prostacyclin infusion did not markedly affect the excretion of the thromboxane metabolite.

A comparison of two stable prostaglandin E analogues for termination of early pregnancy and for cervical dilatation

Termination of pregnancy with prostaglandin E analogues is in general associated with a lower frequency of gastrointestinal side effects than if corresponding F analogues are used. Their clinical use has, however, been limited by stability problems. In the present study the efficacy of different dose schedules of two new stable E analogues for termination of early pregnancy and for preoperative dilatation of the cervical canal was evaluated in 389 women. In early pregnant patients, vaginal administration of 75 mg of 9-deoxo-16, 16-dimethyl-9-methylene PGE2 repeated after six hours or three intramuscular injections of 0.5 mg 16-phenoxy-omega-17, 18, 19, 20-tetranor PGE2 methyl sulfonylamide administered in three-hour intervals resulted in a complete abortion in 94 to 100 per cent of the patients. Both treatments were associated with a low frequency of side effects. The 9-methylene analogue had the advantage of causing less uterine pain than 16-phenoxy-omega-17, 18, 19, 20-tetranor PGE2 methyl sulfonylamide with the dose schedules used. Single vaginal administration of 30 mg of 9-deoxo-16, 16-dimethyl-9-methylene PGE2 and one intramuscular injection of 0.5 mg of the methyl sulfonylamide analogue 12 hours prior to vacuum aspiration were equally effective in dilating the cervix in late first trimester pregnant patients. For both compounds, the frequency of side effects were lower than that previously reported for different PGF analogues administered by non-invasive routes.