Ramesh B. Ghodgaonkar

Myocardial prostaglandin E release by nitroglycerin and modification by indomethacin

In open chest dogs, studies were made of the effects of intravenous trinitroglycerin (10 micrograms/kg per min) on circumflex arterial coronary blood flow, coronary vascular resistance, systemic arterial pressure and myocardial prostaglandin E production before and after indomethacin (n = 9) or indomethacin vehicle (n = 5). During a 30 minute trinitroglycerin infusion, coronary sinus prostaglandin E concentration increased significantly (approximately +41 percent, p less than 0.01) without significant changes in left atrial prostaglandin E concentration. After indomethacin (5 mg/kg), but not indomethacin vehicle alone, a second trinitroglycerin infusion (10 micrograms/kg per min) produced a significantly smaller decrease in coronary vascular resistance (p less than 0.05) and systemic blood pressure (p less than 0.01) and no increase in coronary sinus prostaglandin E (p less than 0.001) by comparison with control values. The heart rate response to trinitroglycerin was significantly greater (p less than 0.05) after than before indomethacin. This study suggests that the mechanism of action of trinitroglycerin may be at least partially mediated through the prostaglandin system.

Cul-de-sac fluid in women with endometriosis: fluid volume and prostanoid concentration during the proliferative phase of the cycle—days 8 to 12 *

Cul-de-sac fluid from women with histologically confirmed endometriosis (n = 45) or with no evidence of endometriosis (n = 17) was removed during the proliferative phase of the menstrual cycle (days 8 to 12) and analyzed for prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), 15-keto-13,14-dihydroprostaglandin F2 alpha (PGFM), and thromboxane B2 (TXB2). The fluid volume was recorded. Peripheral blood was also obtained to determine the concentration of PGFM. Prostanoid concentrations (PGE2, PGF2 alpha, PGFM, TXB2) in women with endometriosis were not significantly different from a comparable group of disease-free women. Furthermore, a meaningful elevation of prostanoid with increasing severity of disease could not be demonstrated. Plasma PGFM was not significantly different from controls. There was, however, an elevation of PGFM with severity of disease, although this increase was not statistically significant (P = 0.11). An increase in fluid volume was not demonstrated in women with endometriosis, as compared with controls.

13, 14-Dihydro-15-keto-prostaglandin F2α concentrations in human plasma and amniotic fluid

An antiserum to 13,14-dihydro-15-keto-prostaglandin F2alpha (PGF2alphaM) was prepared and a radioimmunoassay evaluated in various reproductive states. PGF2alphaM plasma concentration was 63.6 +/- 10.3 pg/ml (mean +/- SEM) in cycling women. The concentration fluctuated throughout the menstrual cycle and pregnancy, but no discernible patterns were noted. PGF2alphaM concentrations were elevated at the time of urea + oxytocin induced abortion (238 +/- 54 pg/ml) and during late stages of normal labor (352 +/- 107 pg/ml) but were not elevated during labor prior to 7 cm dilatation. Following intra-amniotic instillation of 5 mg of PGF2alpha tromethamine into the amniotic sac, PGF2alphaM concentration increased in the amniotic fluid. In the plasma of these patients there was an eighteenfold rise in plasma PGF2alphaM concentration compared to a 3.5-fold rise in PGF2alpha at 1 hour, suggesting changes in PGF2alphaM may be more easily detected than the parent compound. While PGF2alphaM may be a useful index of PGF2alpha production, it appears that PGF2alphaM is of little value in predicting the occurrence of uterine contraction.

Prostaglandin E2 release on the fetal and maternal sides of the amnion and chorion-decidua before and after term labor

Release of prostaglandin E2 on each of the fetal and maternal sides of the fetal membranes (8 cm2) from term cesarean (no labor) and spontaneous vaginal (labor) deliveries was studied with the use of dual-compartment perfusion chambers. Postlabor amnion released significantly (p less than 0.05) more total prostaglandin E2 (5.66 +/- 1.02 ng, mean +/- SEM) than prelabor tissue (3.34 +/- 1.76 ng) with equivalent prostaglandin E2 levels being released on both sides. A net decrease (p less than 0.001) in prostaglandin E2 release by chorion-decidua was identified after labor (fetal = 0.12 +/- 0.05 ng; maternal = 0.17 +/- 0.09 ng) when compared with that before labor (fetal = 1.28 +/- 0.69 ng; maternal = 2.31 +/- 0.56 ng). Amnion-chorion-decidua released more prostaglandin E2 on the fetal side after labor (2.37 +/- 1.43 ng) than prior to labor (1.49 +/- 0.60 ng); however, prostaglandin E2 on the maternal side was significantly less (p less than 0.05) after labor (0.24 +/- 0.12 ng) when compared with that of the prelabor membrane (2.03 +/- 1.08 ng). Elution of prostaglandin E2 from preincubated membranes and endogenous membrane prostaglandin E2 content showed similar results. Thus concentrations of prostaglandin E2 on the maternal side of the fetal membranes appear diminished after spontaneous labor despite an increased release from the fetal surface.

Effect of hydrogen peroxide on prostaglandin production and contractions of the pregnant rat uterus

Although evidence for a role for prostaglandins in parturition is abundant, less is known about how prostaglandin levels are regulated at term. Conditions occurring peripartum in the uteroplacental unit can result in reactive oxygen production. We investigated the effect of one reactive oxygen product, hydrogen peroxide, on in vitro activity of uterine segments from the 18-day-pregnant rat. H2O2 (0.3 mmol/L) was found to elicit rhythmic contractions and increase prostaglandins F2 alpha and E2 release by uterine tissue. Indomethacin blocked both of these effects. We conclude that H2O2 stimulates uterine contractions through a prostaglandin release mechanism. A speculative hypothesis of peripartum regulation of prostaglandin production by reactive oxygen is discussed.

Cul-de-sac fluid in women with endometriosis: fluid volume, protein and prostanoid concentration during the periovulatory period−days 13 to 18

Cul-de-sac fluid from women with histologically confirmed endometriosis (n = 45) or from infertile women without evidence of endometriosis (n = 28) was collected at the time of laparoscopy during the periovulatory period (days 13 to 18). This fluid was analyzed for prostaglandin E2 (PGE2), prostaglandin F2a (PGF2a), 13,14-dihydro-15 keto-PGF2a (PGFM), and thromboxane B2 (TXB2) by radioimmunoassay (RIA). Protein content of the fluid also was determined. No difference (P greater than 0.05) in cul-de-sac fluid volume was found between women with and without endometriosis, nor were differences detected in the level of any of the prostanoids measured in fluid from infertile control patients compared with those with endometriosis. This was true regardless of whether the prostanoids were expressed as a concentration, total amount in fluid, or as a ratio of prostanoid to protein content. The present study does not support the theory that cul-de-sac fluid prostanoids provide a useful diagnostic index of endometriosis.

Effects of systemic administration of indomethacin on ovulation, luteinization, and steroidogenesis in the rabbit ovary

Indomethacin blocks ovulation in human chorionic gonadotropin-stimulated rabbits. Experiments were done with an in vitro ovarian perfusion system to investigate whether indomethacin affects luteinization and steroidogenesis. Indomethacin (10 mg/kg) was administered in combination with human chorionic gonadotropin (100 IU) via a marginal ear vein, and a second dose of indomethacin was given 8 hours later. Control animals received vehicle in place of indomethacin. Laparotomy was performed 24 hours after the initial treatment. The presence of unruptured follicles and corpora lutea was recorded and the ovaries were perfused in vitro for 3 hours. Progesterone, prostaglandin F2 alpha, prostaglandin E2, and 6-keto-prostaglandin F1 alpha were measured in samples obtained at 0, 30, 60, 120, and 180 minutes from the circulating perfusion medium entering and exiting the ovary. At the end of the perfusion all ovaries (12 treated and 10 controls) were fixed for histologic analysis. Ovulation occurred in all control ovaries but in none of the indomethacin-treated ovaries. The mean number of unruptured follicles per ovary in the treated group was not significantly different from the number of corpora lutea plus unruptured follicles per ovary in the controls. Cells in both groups were qualitatively similar in ultrastructure; abundant lipid droplets, smooth endoplasmic reticulum, and mitochondria were seen. Secretion rates of progesterone and prostaglandin did not differ between the two groups during the 3-hour perfusion period. These results suggest that transformation of granulosa cells into fully functional luteal cells can occur in the absence of follicular rupture.

Effect of intrauterine administration of tetracyclines on cynomolgus monkeys

Cynomolgus monkeys were used to screen for chemicals which potentially could be used as tubal occluding agents. Intrauterine administrations of solution or pellets of tetracycline and its analogues (100 mg doses) were tested for their effects on morphologic changes in the reproductive tract of monkeys. These effects were compared to monkeys receiving intrauterine administration of quinacrine pellets (36 mg) since quinacrine has been used successfully in the clinical setting. Blood levels of drugs, blood chemistry and hematology determinations and liver and kidney pathology data were also obtained as indices for toxicity. Morphologic damage to the uterine lining and intramural section of the tube (including necrosis, inflammation or scarring) was elicited by intrauterine tetracycline and doxycycline in the same frequency and severity as quinacrine. In contrast, saline or sham control monkeys showed no morphological damage of the tube or uterus. Although all drugs could be detected in the blood 4 hours after intrauterine administration, levels were near or below the limit of detection by one week. No evidence was found for toxicity of tetracycline or its analogues for the dosage given. Because of these results and the extensive literature on tetracycline toxicity, further studies should be directed toward the use of tetracycline as a sterilizing agent in women.

Comparative effects of intrauterine instillation of analogues of quinacrine and tetracycline on uterine morphology in the rat

Currently, intrauterine instillation of quinacrine hydrochloride is used to induce closure of the uterotubal junction in women, thus constituting a chemical method of sterilization. Questions regarding the safety of this drug have been raised. The purpose of the present study is to screen other drugs for their sterilizing potential by comparing quinacrine-induced changes in uterine morphology in the rat which have previously been correlated with decreased fertility with the changes induced by other drugs. The drugs tested include quinacrine-like compounds, namely chloroquine, primaquine and trimethoprim; and tetracycline and its analogues which are known sclerosing agents. The quinacrine-like drugs were relatively ineffective in producing uterine lesions similar to those of quinacrine, but like quinacrine, chloroquine and primaquine showed some toxicity. Tetracycline and its analogues produced quinacrine-like morphologic changes in the rat uterus and showed no toxicity for the doses tested. These results prompt further testing of tetracycline and its analogues as sterilizing agents.

Uterine activity and prostaglandin production following intraamniotic hyperosmolar urea.

The relationship between endogenous prostaglandin (PG) production and uterine activity was studied in hyperosmolar urea induced abortion patients. Polygraphic recordings of intraamniotic pressure were obtained at periodic intervals following intraamniotic injection of 80 gm urea. At 0, 0.25, 1, 4 and 8 hours amniotic fluid and blood samples were obtained for PGE, PGF and 13,14-dihydro-15-keto-prostaglandin of abortion. In eight patients studied, uterine tone was elevated by 0.25 hour although no rhythmic contractions were observed by 1 hour. At 4 hours, amniotic fluid PGF concentration increased significantly (P less than .01) over the pre-injection value and continued to increase at 8 hours. Amniotic fluid PGE, PGFM and all plasma PGs showed no change during the 8 hour period following urea administration. At time of abortion the plasma PGFM concentration was significantly. At time of abortion the injection (238 +/- 54.4 vs. 86.7 +/- 7.3 pg/ml). There was no significant concentrations. In the present study, there is no evidence that increased prostaglandin production precedes urea induced contractions. The possible role of PGs in uterine contractions is discussed.