Progesterone and 20 alpha-dihydroprogesterone in human myometrium during pregnancy

Double-blind controlled trial of progesterone substitution in threatened abortion

Gerhard I et al., 1987 · Biol Res Pregnancy Perinatol

Between 1983 and 1984 a double-blind randomized study with progesterone substitution in threatened abortion was carried out. Fifty-six patients with vaginal bleeding during the first trimester of pregnancy, the internal cervical os being closed, were referred to the hospital. Twenty-five women (5th and 6th week of gestation) with positive serum concentrations of beta-hCG were admitted to the study without regard to sonogram results. In other 25 women (7th-10th week of pregnancy) and 6 women (greater than or equal to 11th week of pregnancy) fetal heart action and movement could be demonstrated by ultrasound. The patients were prescribed bed rest and vaginal suppositories twice daily, containing either 25 mg progesterone or only polyethylene glycol. The code was not broken until after completion of the study. Serial serum determinations of beta-hCG, estradiol-17 beta (E2), progesterone, and ultrasound were performed. Four patients had to be omitted from final analysis (two tubal pregnancies, one intrauterine infection, one sectio parva). Three of 26 patients progesterone (11%) and five of 26 patients with placebo (19%) had an abortion, which represented no significant difference. Frequency of abortion was increased in women more than 30 years old, in women with previous abortions and after ovulation induction. Progesterone treatment resulted in a significant elevation of serum progesterone concentrations (p less than 0.01), while beta-hCG and E2 were unchanged. The results of this study confirm that pregnancy outcome is favorable in women with bleeding and normal hormone concentrations without hormonal treatment and unfavorable in women with reduced beta-hCG and E2-concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Progesterone in human blood and tissues

Zander J, 1954 · Nature

THE problem as to whether progesterone is present in human peripheral blood, and in what concentrations, has not yet been solved satisfactorily.

High affinity progesterone binding sites of human uterine microsomal membranes

Haukkamaa M, 1984 · J Steroid Biochem

Microsomal membranes sedimented at 40 000 g were prepared from human myometrium samples. The progesterone binding properties of microsomal suspensions were determined by incubating microsomes and [3H]progesterone at 4 degrees C. Dextran-coated charcoal was used for the separation of bound and free steroids. Membrane-associated progesterone binding sites of high affinity were identified in microsomes prepared from pregnant and nonpregnant uteri. The binding was saturable (Kd approximately 4 X 10(-9) M, concentration of binding sites 400-900 fmol/mg microsomal protein) and specific for natural progesterone. Of 21 steroids tested only 21-hydroxy-4-pregnene-3,20-dione, 17 alpha-hydroxyprogesterone and testosterone showed moderate competition against progesterone with relative affinities between 7.0-20.0% (R.A. of progesterone 100%). 5 alpha-Dihydroprogesterone and 5 alpha-dihydrotestosterone showed weak cross reaction (relative affinities 2.5 and 2.0%, respectively). Corticosteroids, estrogens and the 5 synthetic progestins tested showed only weak competition with relative affinities lower than 1.0%. These microsomal progesterone binding sites of high affinity and limited capacity resemble steroid hormone receptors but they are different from the soluble cytosolic progesterone receptor of human uterus in terms of steroid specificity. The physiological function of this microsomal progesterone receptor is unknown.

17 beta-Estradiol and progesterone concentrations in myometrium of pregnancy and their relationships to concentrations in peripheral plasma

Batra S et al., 1978 · J Clin Endocrinol Metab

17 beta-Estradiol (E2) and progesterone (P) concentrations in blood and in the myometrium of human pregnancy at term (n=33) and in a few samples (n=5) around midterm of pregnancy were determined. E2 concentration in the myometrium (per g wet wt) at midterm was lower than the concentration in the plasma (per ml) so that the myometrium to plasma (My:Pl) ratio was 0.7. Relative to plasma concentration, the myometrial E2 increased little from midterm to term so that My:Pl was only 0.2 at term. Although P concentration in the myometrium was much greater than that in the plasma at midterm, My:Pl ratio being 2.2, it was lower than that in plasma at term so that My:Pl ratio was only 0.6. A fairly good correlation between plasma steroids and the myometrial steroids was observed at midterm but was distorted at term, probably due to saturation of the tissue-binding capacity. Steroid concentrations determined on the basis of protein showed a good correlation to the values expressed on the basis of wet weight. Whereas myometrial E2 concentration was significantly influenced by the distance from placenta, P concentration was not.

In vitro inhibitory effect of progesterone on extrauterine human smooth muscle

Kumar D, 1962 · American Journal of Obstetrics and Gynecology

Oral administration of micronized natural progesterone in late human pregnancy. Effects on progesterone and estrogen concentrations in the plasma, placenta, and myometrium

Ferre F et al., 1984 · Am J Obstet Gynecol

A single dose of micronized oral progesterone was administered to 15 pregnant women immediately prior to elective cesarean section. Levels of progesterone, 17 beta-estradiol, and estrone were measured in the plasma, in the placenta, and at different sites in myometrium obtained during the surgical procedure. Results were compared to those observed in a control group of women who did not receive progesterone. Progesterone levels demonstrated a marked increase in plasma and in the whole myometrium 150 minutes after administration. The levels then decreased rapidly to control values in 1 hour. The concentrations of progesterone in the placenta did not show any changes. No difference appeared in 17 beta-estradiol levels in the plasma or the myometrium, whereas an increase was observed in the placenta. Estrone levels did not change in the plasma, but they decreased in the myometrium and in the placenta.