Injection Of Prostaglandin F2 Alpha Research Articles

Cardiovascular and sympathetic responses to PGF 2 α injection into hypothalamic nuclei

Injection of prostaglandin F2 alpha (1 nmol/rat) into the paraventricular, dorsomedial and posterior hypothalamic nuclei of halothane anesthetized rats elicited rapid increases of heart rate and blood pressure. The injection of this same dose of prostaglandin F2 alpha into the cerebroventricular system or intravenously had no effect on these parameters. The cardiovascular responses observed following prostaglandin F2 alpha injection into these hypothalamic nuclei were accompanied by increases in plasma levels of norepinephrine and epinephrine, with peak levels at the maximal cardiovascular response. This study suggests a possible role for prostaglandin F2 alpha in modulation of the cardiovascular system via specific hypothalamic nuclei.

The differential effect of progesterone on concentrations of luteinizing hormone and follicle-stimulating hormone in heifers.

The effects of progesterone on LH and FSH concentrations in cattle are not clearly understood. The objective of this experiment was to determine the effect of various concentrations of progesterone on serum concentrations of LH and FSH in heifers. After estrous synchrony, animals were assigned to four different treatment groups (n = 10/group). Heifers received vaginal coils containing either 2% or 6.75% progesterone between days 8-10 (luteal phase) or days 17-18 (follicular phase) after estrus. Coils remained in place for 7 days. One day before removal of coils, all animals received an injection of prostaglandin-F2 alpha to cause regression of existing corpora lutea. Both the stage of the cycle and the percentage of progesterone in the coil affected serum concentrations of progesterone while the coils were in the vagina. Concentrations of FSH during progesterone treatment were not different for animals on different treatments. While coils were in the vagina, there was a significant increase in serum LH concentrations in heifers in the follicular phase given 2% progesterone coils, but no increase in LH was observed in the other three treatment groups. After removal of the progesterone coils, but before the preovulatory gonadotropin surges, LH increased but not FSH. The LH and FSH surges occurred synchronously. After the surges, FSH concentrations increased at a faster rate than LH. These data suggest that differential feedback mechanisms exist for LH and FSH in heifers. (Endocrinology 108: 568, 1981)

Uterine rupture: A complication of midtrimester abortion

The intraamniotic injection of prostaglandin F2alpha and/or hypertonic saline may be associated with serious uterine and cervical trauma. Multiparity and superimposed uterotonic stimulation by oxytocin are generally thought to be contributory. A patient is described who failed to abort vaginally after an uneventful intraamniotic infusion of prostaglandin F2 alpha in combination with hypertonic saline; 48 hours later she evacuated the uterine contents into the peritoneal cavity through a rent in the uterine fundus. The uterine rupture occurred even though there had been no uterotonic stimulation by oxytocin.

The use of prostaglandin F2 alpha in selective hepatic angiography.

Comparison has been made between slow infusion hepatic angiographic studies obtained before and after the intra-arterial injection of prostaglandin F2 alpha. The prostaglandin injection resulted in increased caliber of the hepatic arteries, increased opacification of the parenchyma of the liver and improved visualization of the wall of the gallbladder. Poorly vascularized metastatic lesions were better shown on the prostaglandin studies, and carcinoma of the gallbladder was diagnosed in two instances. The demonstration of highly vascularized metastatic tumor was enhanced on the prostaglandin studies, but further improved after the injection of angiotensin.

The placental and fetal response to the intra-amniotic injection of prostaglandin F2alpha in midtrimester abortions.

The placental and fetal response to the intra-amniotic injection of prostaglandin F2alpha (PGF2alpha) for midtrimester abortions was evaluated. Maternal blood samples for radioimmunological determinations of serum progesterone, human placental lactogen (HPL) and alpha-fetoprotein (AFP) were taken before and serially until 24 hours after the injection of 40 mg (nine patients) or 75 mg (seven patients) of PGF2alpha. Fetal heart action was monitored ultrasonically during the same period. The average induction-abortion interval was 22-6 hours and was indepedent of the dose of PGF2alpha used. The mean progesterone and HPL levels showed a significant fall half an hour after PGF2alpha. The constant decreases began only at 5 hours and later. The mean AFP levels increased rapidly after 5 hours following injection of PGF2alpha. The feral heart stopped at a mean of 10-4 hours (range 0-5 to 25 hours) after the injection of PGF2alpha. No relationship between the time of fetal death or rises in AFP and the induction-abortion interval could be detected. The primary hormonal response of the placenta and the efficacy of exogenous PGF2alpha were not related, indicating the possibility that the abortifacient property of PGF2alpha is not related to its primary effect on placental hormone synthesis or release.

Terbutaline inhibition of midtrimester uterine activity induced by prostaglandin F2alpha and hypertonic saline.

The effect of the beta receptor stimulator, terbutaline, on uterine activity induced by intra-amniotic injection of prostaglandin F2alpha or hypertonic saline was investigated in 20 patients undergoing therapeutic abortion in the second trimester. Intrauterine pressure was recorded, and the basal tone, intensity and frequency of contractions and "total" activity (expressed in Montevideo Units or MU), were measured. Uterine activity was higher in the prostaglandin group (mean value 393 MU) than in the hypertonic saline group (mean value 238 MU). However, terbutaline, infused at a rate of 5 to 20 mug/minute, decreased the activity by approximately the same absolute amount in the two groups to a mean value of 214 MU in the prostaglandin group and to 68 MU in the saline group. In some patients of the saline group, terbutaline completely inhibited uterine contractions. Basal tone, which was high in the prostaglandin group (mean value 28 mm Hg) decreased to a mean value of 17 mm Hg during terbutaline infusion. In the saline group the mean value for basal tone decreased from 10-5 to 7-5 mm Hg. It is concluded that uterine activity, induced by intra-amniotic injection of prostaglandin F2alpha or hypertonic saline, can be inhibited by terbutaline. The mechanisms of action for prostaglandins and hypertonic saline are discussed.