Total Progesterone Research Articles

Hormone levels in the normal menstrual cycle.

Hormone levels in the normal menstrual cycle were investigated during 6 cycles. 24-hour urine samples basal body temperatures and blood samples were obtained daily for comparison and measurements of uri nary and plasma luteinizing hormone (LH) urinary follicle stimulating hormone (FSH) urinary total estrogens plasma estrogens plasma progesterone and urinary pregnanediol. Urinary LH levels followed the usual biphasic pattern with an early follicular phase rise beginning before menstruation and lasting for 4 days. Urinary FSH also showed an early follicular phase rise and a midcycle peak coincident with urinary LH. Urinary estrogens showed the typical biphasic curve and plasma estrogens (estrone and estradiol) showed fluctuating levels in the follicular phase rising to a peak 1 day before the urinary LH and total urinary estrogen peaks. Progesterone in the follicular phase was less than .8 ng/ml and then rose to 14.7 ng/ml on Day 21 of the composite cycle. The 1st marked rise was seen 1 day after the urinary LH and total estrogen peak and 48 hours after the plasma LH and plasma estrogen peak.

Dietary Urea for Dairy Cattle. I. Relationship to Luteal function

Isonitrogenous complete mixed rations containing concentrates, corn silage, and ground corn cobs, differing only in source of supplemental nitrogen (Group I—soybean meal and Group II—urea), were fed to Holstein-Friesian heifers for a minimum of 60 days. The purpose was to study the effect of dietarv urea on luteal function. Jugular blood and corpora lutea were collected on Day 12 after estrus. Average concentrations of progesterone, luteinizing hormone, corticosterone, and cortisol in blood plasma were approximately the same for both groups. Ten corpora lutea from Group I were heavier (P<.005) than the 12 from Group I1 (6.4±.6g versus 4.3±.3g). The corpora lutea from Group II were softer and more fragile than those from Group I, but there were no discernible histological differences. The contents and concentrations of progesterone and 20β-hydroxy-pregnene-3-one in unincubated corpora lutea were not significantly different between treatments. However, corpus luteum tissue from Group I as compared to Group I1 synthesized more progesterone (P<.05) during in vitro incubation in blood plasma (2 hr at 37C) and contained more total progesterone (P<.05) after incubation. Source of jugular plasma substrate, either from Group I or Group II, had no significant effect on synthesis of progesterone. The relationship between differences in corpus luteum function due to ration and reproductive efficiency was not determined.

PROGESTERONE AND 20α-DIHYDROPROGESTERONE IN HUMAN MYOMETRIUM DURING PREGNANCY

PROGESTERONE AND 20α-DIHYDROPROGESTERONE IN HUMAN MYOMETRIUM DURING PREGNANCY

Progesterone in uterus and plasma. IV — Progesterone receptor(s) in guinea pig uterus cytosol

After injection of 3H-progesterone to estradiol primed castrated guinea pigs, a radioactive 6.7 S peak was found in the uterus cytosol by sucrose gradient ultracentrifugation in tris 10 mM. It was abolished by heating for 20 min at 60° C or by parahydroxymercuribenzoate treatment. The same peak was observed after direct incubation of the uterus cytosol with 1 nM 3H-progesterone. The association constant with progesterone was approximatively 2.10 9 M −1. In 0.3 M KCl medium, the sedimentation coefficient of the peak shifted to 4.3 S. 5α-pregnanedione and 17α-ethinyl nor testosterone competed for progesterone binding sites but cortisol, testosterone or estradiol did not. The receptor was not found in the plasma or in kidney, intestine and muscle cytosol. Another progesterone binding peak was observed in the 4–5 S region of the uterine cytosol. Estradiol treatment increased the total progesterone binding with an especially marked increase of the 6.7 S binder. The receptor was different from the guinea pig Progesterone Binding Plasma Protein (PBP).

SIALIC ACID CONTENT AND SPERM PENETRATION OF CERVICAL MUCUS IN RELATION TO TOTAL URINARY OESTROGEN EXCRETION AND PLASMA PROGESTERONE LEVELS IN OVULATORY WOMEN

In 6 regularly menstruating women ages 23 to 34 years daily measurements of sialic acid (SA) content and sperm penetration into the cervical mucus (CXM) were related to the total urinary estrogen excretion and plasma progesterone levels during 1 ovulatory cycle. In 4 women of known fertility and in 1 normally menstruating woman the peak in sperm penetration and the dip in sialic acid content occurred almost simultaneously with the ovulatory peak in urine and preceded the probable ovulation by 1 day. Sperm capacitation appears to be necessary for fertilization in the human. The occurrence of peak sperm penetration before ovulation would thus result in a period of time for capacitation to take place. In 1 woman who had been barren for several years the steroid patterns were normal but the peak of sperm penetration and the dip in sialic acid content occurred 1 day after ovulation. The possible significance of this observation is noted especially since her husbands sperm samples were considered normal. Techniques of the daily sample-collecting of CXM urine and venous blood samples are given; SA technique is given. Sperm penetration tests were done using the capillary method. No free SA was found in any sample of CXM. Data are in agreement with those reported by others.

Exogenous Hormones and Luteal Function in Hysterectomized and Intact Heifers

Groups of five Holstein heifers were hysterectomized on Day 10 of the estrous cycle, and beginning 21 days later were given daily injections of either oxytocin, estradiol, equine luteinizing hormone, adrenocorticotropin, or relaxin. Three additional groups were slaughtered at the end of six, 15, and 30-day control periods. A gradual decrease in luteal tissue weight, progesterone concentration, and 20-β-ol concentration occurred as the control period lengthened. Oxytocin injections (0.33 United States Pharmacopoeia (USP) units/kg body wt/day) for either 15 or 30 days had no luteolytic effect. Equine luteinizing hormone (20 mg/day for 15 days) significantly increased progesterone concentration, total progesterone, and total progestins. Estradiol (5 mg/day) administered to one group for six days and to another for 15 days significantly depressed 20-β-ol concentration, total progesterone, and total progestins. Estradiol injected into intact heifers on either Days 5 through 14, or 10 through 14 caused complete luteal regression. Relaxin injections into hysterectomized heifers for 15 days had no effect. Adrenocorticotropin (100 units/day) injected on Days 2 through 8 significantly decreased corpus luteum weight in intact Hereford heifers, but was ineffective when injected into hysterectomized heifers. These results indicate that a uterine luteolytic mechanism is necessary for complete luteal regression, or that the corpora lutea of hysterectomized cows are unresponsive to normal luteolytic mechanism (s).

Protein binding of progesterone in the peripheral plasma during pregnancy and labor

This study was designed to determine the plasma levels of free and protein bound progesterone during normal pregnancy and labor in women. The total progesterone concentration was determined by gas-liquid chromatography and the percent protein bound by equilibrium dialysis during weeks 8, 17, 21, 28, 34, 38 and 40 of pregnancy and in 2 serial studies 1 week before and during spontaneous labor (15 determinations). The steroid-protein binding percentages were obtained using equilibrium dialysis at 37°C with diluted plasma samples. The percent of progesterone which was protein bound remained constant at 90.5 ± 1.2% throughout pregnancy and labor. This was similar to a 91.1 ± 0.6% binding of progesterone in a normal menstrual cycle (6 determinations). Since the total progesterone was highest in late pregnancy and labor, the free or biologically active progesterone was also maximal at the onset of labor. This finding in the peripheral blood does not substantiate the concept that a “progesterone withdrawal” is associated with the institution of parturition.

Luteal function in the merino ewe and the effect of exogenous progestagen.

SUMMARY Progesterone levels were determined in the ovarian and jugular vein plasma and the corpus luteum of 68 cyclic Merino ewes (controls) and of 32 ewes which had been treated with intravaginal sponges containing a synthetic progestagen (Cronolone, Searle). The weight and diameter of the corpus luteum and the rate of flow of the ovarian vein blood were also recorded. No corrections for procedural losses were made. The control ewes showed highly significant (P &lt; 0·001) cyclic changes in the progesterone contents of the ovarian vein plasma and the corpus luteum, and in the mass of the corpus luteum. There were positive correlations (P &lt; 0·001) between ovarian vein plasma progesterone concentration and the weight (r = 0·651), diameter (r = 0·692), total progesterone content (r = 0·775) and progesterone concentration (r = 0·574) of the corpus luteum. Cyclic changes in the progesterone content of the jugular vein failed to attain significance (0·1 &lt; P &lt; 0·2) but the levels were positively correlated with those in the ovarian vein (r = 0·465, P &lt; 0·001) and with weight (r = 0·432, P &lt; 0·001) and diameter (r = 0·303, P &lt; 0·05) of the corpus luteum. The Cronolone-treated ewes showed cyclic changes in luteal function similar to those in controls, with the exception of animals treated on the day of oestrus. In ewes in which ovulation was not suppressed, the duration of activity of the corpus luteum, as measured by progesterone concentration in ovarian vein plasma, and concentration and content in the corpus luteum was significantly reduced. By the 12th day of the cycle the corpus luteum had almost completely regressed both morphologically and functionally.

The effect of antisera to bovine LH in hysterectomized and intact heifers.

Injection of antiserum to bovine LH into hysterectomized heifers caused significant decreases in corpus luteum weight, total progesterone, total progestins and 20�-hydroxypregn4-en-3-one (204-01) concentration but had no effect on progesterone concentration. Gonadotropin secreting cells in the anterior pituitaries of these heifers were markedly degranulated and pituitary LH contents lowered. Thyroid epithelial cell heights were lowered suggesting that the antiserum also contained anti-TSH. The administration of antibovine LH to cyclic heifers from Day 2 to Day 6 of the cycle caused a significant decrease in corpus luteum weight and total progesterone content, but only a slight decrease in progesterone concentration. Histological signs of regression were clearly evident in the corpora lutea of the hysterectomized anti-LH treated heifers, but little difference could be noted between the corpora lutea of control and treated cyclic animals. Injection of 50 ml of antibovine LH daily from Day 2 to Day 6 of the cycle increased the interval between corpus luteum removal at Day 11 and return to estrus. Injections of 50 ml of antibovine LH daily from Day 12 to Day 16 and from Day 16 to Day 20 of the cycle increased the lengths of the treatment cycles to 28.5 and 36.7 days, respectively. The first post-treatment cycle in both groups was significantly shortened. The increase in cycle length was primarily due to a failure of follicles to develop to mature size, rather than to prolongation of the life span of the corpora lutea. The results of these experiments indicated that LH is required for follicular development and maturation and for the induction of estrus, as well as for corpus luteum maintenance.

Transcortin: a corticosteroid-binding protein of plasma. X. Cortisol and progesterone interplay and unbound levels of these steroids in pregnancy.

ABSTRACT The concentrations of total cortisol, progesterone and transcortin rise during pregnancy. Unbound cortisol shows a gradual increase during pregnancy, its level rising to about 3 times the concentration in normal plasma and in proportion to the rise of the total cortisol concentration. The level of unbound progesterone rises in the course of pregnancy, approximately in proportion to the total progesterone concentration. Progesterone replaces transcortin-bound cortisol increasingly during pregnancy until, in its later stage, the ratio of transcortin-bound progesterone to transcortinbound cortisol becomes about 0.3. The computed value for the association constant of the cortisol-transcortin complex in pregnancy plasma is about 12 μm−1 and that of the progesteronetranscortin complex is about twice this value.

Secretion of pregn-4-ene-3,20-dione (progesterone) in vivo by the adrenal gland of the rat.

Feder, Resko and Goy1 suggested recently that the adrenal gland of the rat secretes progesterone. They observed that the arterial blood of female rats still contained significant amounts of progesterone 25 days after bilateral ovariectomy; 8 h after additional adrenalectomy, however, the steroid was no longer detectable. Because the rat is often used for experiments in reproductive physiology, it is important to assess the contribution of the adrenal gland to the total available progesterone in the female rat. We have therefore measured the secretion of progesterone from the adrenal gland by estimating the amount of the steroid secreted into the adrenal venous blood. Experimental conditions were maintained comparable with those used recently for measuring the secretion of progesterone by the ovary of the rat2–4.

The effect of exogenous oxytocin on corpus luteum function in the cow.

Summary. Seventy-seven Hereford cows were used to study the effects of oxytocin (0, 2, 6 or 18 USP units/100 lb live weight) on corpus luteum function (net weight, progesterone concentration and total progesterone content). Oxytocin was injected in the morning (a.m.) or evening (p.m.) according to four injection regimes. Calling day of oestrus Day 0, oxytocin was injected on Days 2 to 5 and the corpus luteum collected on Day 5 (regime 1) or Day 9 (regime 2). Oxytocin was injected on Days 2 to 7 (regime 3) or 2 to 9 (regime 4), and the corpus luteum collected on Day 9. There was no effect of time of injection on corpus luteum net weight, progesterone concentration or total progesterone content over all doses and regimes. However, within doses 2 and 6 units, corpus luteum total progesterone was less affected by p.m. than a.m. injection. The opposite effect was observed when 18 units oxytocin injected a.m. in regime 2 did not reduce corpus luteum total progesterone to the same extent as in other high dosage treatment groups. The 2 units dose of oxytocin stimulated total progesterone content of corpora lutea in regime 2. Increase in the dose or number of days of injections reduced corpus luteum net weight, progesterone concentration and total progesterone. A significant dose-response relation was demonstrated between corpus luteum net weight, progesterone concentration and total progesterone and dose of oxytocin when oxytocin was injected on Days 2 to 5 (p.m.) and the response measured on Day 9 ; or when oxytocin was injected either a.m. or p.m. on Days 2 to 7 or 2 to 9 and the response measured on Day 9. It was concluded that there may be a diurnal response in corpus luteum functions to oxytocin injections and a critical time on Day 5 through which injections must be made to elicit a maximum dose response in corpus luteum weight, progesterone concentration and progesterone content.

Progesterone in the corpus luteum and placenta of the armadillo, Dasypus novemcinctus.

Summary. The progesterone content of corpora lutea from armadillos in the delayed implantation period and both corpora and placentae from animals in the post-implantation period was determined chemically. During the delay period the weight of the corpus luteum, but not the total progesterone content (μg/gland), was significantly higher in animals carrying blastocysts than animals without blastocysts. Following implantation of the blastocyst, the size as well as the total progesterone content increased significantly (P<0·05). However, during the latter part of the post-implantation period (> 6 cm crown-rump length) both the size and the progesterone content decreased by more than two-fold (P<0·05). However, at this stage considerable amounts of progesterone were found in placentae and in one uterine vein blood sample studied. In contrast, no hormone could be detected in the placenta of earlier stages (i.e. <5 cm crown-rump length). These data suggest that the functional activity of the corpus luteum may be lower during delayed implantation than in the early post-implantation period. However, during the latter part of gestation the corpus luteum regresses, and it is probable that at this stage the placenta contributes significant amounts of progesterone.

Effects of a Single Injection of Estrogen Early in the Estrous Cycle on Pituitary and Luteal Function in Ewes

Twenty-four mature ewes were studied to determine the effect of a single injection of estradiol−17β on pituitary and ovarian function. Twelve ewes received an intramuscular injection of 2 mg. of estradiol−17β the morning of day 5 and were killed the afternoon of day 7 (approximately 56 hr. later). Six untreated controls were killed on day 5 and six on day 7 of the estrous cycle. New ovulations were observed in eight of 12 treated ewes. Estrous behavior was induced in three of eight ewes which ovulated and one ewe that failed to ovulate. LH activity in pituitaries of estrogen treated ewes was significantly less than that observed for controls killed on the same day of the cycle, indicating an LH release which presumably led to the new ovulations. The total progesterone content of corpora lutea of estrogen treated ewes was significantly depressed by the treatment.

Compensatory ovarian function during pregnancy in the pig.

The effects of unilateral ovariectomy, unilateral hysterectomy or both on ovarian function were investigated in pigs at day 25 of pregnancy. Removal of 1 ovary during early pregnancy (day 5) resulted in increased ovarian and corpora lutea weight and larger graafian follicles in the remaining ovary. Total progesterone, DNA and RNA content of these individual corpora lutea were higher than thoso found in corpora lutea of animals with 2 ovaries. Nucleic acid content indicated that increased corpora lutea weight following removal of 1 ovary resulted from an increase in cell number. Total progesterone, RNA and DNA content of corpora lutea were higher in animals with 2 ovaries. However, the concentrations of progesterone, RNA and DNA in luteal tissue were not affected by removing 1 ovary, 1 uterine horn or both. Reduction of the number of embryos by removal of 1 uterine horn had no significant effect on these parameters. (Endocrinology 81: 430, 1967)

Progesterone biosynthesis in perfused corpora lutea.

SummaryCorpora lutea of isolated luteal-phase swine ovaries perfused with a blood substitute synthesize progesterone without being stimulated by HCG. Synthesized progesterone was isolated by solvent extraction and thin layer chromatography. The isolated progesterone was identified by thin layer chromatography, gas chromatography, ultraviolet absorption spectra, and 2, 4 dinitro-phenylhydrazone derivatives. Small but detectable amounts (less than 0.5% of the amount theoretically possible) of acetate-1-C14 were incorporated into the synthesized progesterone. Most of the progesterone (88% ± 12%) was found in the corpora lutea with the remainder in the perfusate. An average value of 43 μg of progesterone per gram of luteal tissue was synthesized during the per fusion period. Newly synthesized progesterone represented an average value of 45% of the total progesterone isolated from corpora lutea and perfusate.

Luteotropic Properties of Luteinizing Hormone and Nature of Oxytocin Induced Luteal Inhibition in Cattle

Fifty-three Holstein heifers were used to study the effects of oxytocin administered alone and in combination with various gonadotropins on the weights and progesterone contents of corpora lutea. Pituitary gonadotropin levels were compared in untreated and oxytocin-treated heifers at three stages of the estrous cycle.Oxytocin injections on Days 2 through 6 significantly reduced the weights and total progesterone contents but not the progesterone concentrations of glands removed on Day 7. The concurrent administration of either purified bovine luteinizing hormone (LH) or human chorionic gonadotropin (HCG) significantly increased these parameters from the oxytocin treatment levels to normal or supra-normal values. Neither purified bovine prolactin nor urea-incubated HCG overcame the inhibitory effects of oxytocin. Neither oxytocin treatment on Days 2 and 3 nor oxytocin together with HCG significantly altered luteal function when the glands were taken on Day 4.It was concluded that LH is the luteotropic hormone and that the cow requires at least two periods of luteotropic stimulation for normal corpus luteum development: one at ovulation and another after Day 4 of the cycle.Oxytocin depleted total pituitary gonadotropin levels by about half during estrus or on Day 7, but did not alter levels at Day 4.Heifers’ pituitary gonadotropin levels and the total progesterone in their corpora lutea were negatively correlated in control (−0.75 on Days 4 and 7 pooled) and positively correlated in oxytocin- (0.78 on Days 4 and 7 pooled) treated groups (P<0.0001). On Day 7 the correlation coefficient in the oxytocin-treated group was 0.96. The positive correlations in the treated animals are interpreted to mean that pituitary gonadotropin levels reflect plasma levels, and that these levels are directly controlling (and limiting) progesterone synthesis in the corpus luteum. The negative correlations reflect pituitary storage of gonadotropin.

Ovarian Function in Dairy Heifers Following Hysterectomy

Summary Follicular growth, ovulation, corpus luteum formation, and luteal regression were investigated in hysterectomized dairy heifers. Simultaneous hysterectomy and corpus luteum removal were followed by relatively normal follicular growth, ovulation, and corpus luteum formation in five of seven heifers. These post-operative corpora lutea appeared to persist similarly to those formed prior to hysterectomy. Corpora lutea formed prior to hysterectomy and marked for future identification at the time of hysterectomy in 12 heifers failed to regress. When these corpora lutea were examined 20 days after hysterectomy, their total progesterone content equalled that of corpora lutea removed 9–11 days postestrus. However, the persistent corpora lutea differed in that they contained appreciable levels of Δ 4 -pregnen-20B-ol-3-one in addition to progesterone. Ten daily injections of crude or urea-incubated aqueous extracts of bovine hypophysial tissue did not decrease the progesterone content of the corpora lutea which persist following hysterectomy. On the contrary, administration of the crude extracts increased the total weight and progesterone content of many of the corpora lutea; extracts previously incubated with urea to inactivate the luteinizing hormone component had no stimulatory effect on the corpora.

Nature of the Luteotropic Hormone in the Bovine

The ability of daily oxytocin injections to inhibit the growth of the corpus luteum and cause precocious estrus in the bovine was used as a tool to test the luteotropic properties of various gonadotropins and growth hormone. Corpora lutea were collected from each of 32 Holstein heifers at 11 days post estrus after the following treatments: (1) daily oxytocin injections (15 USP units/cwt), (2) daily oxytocin plus gonadotropin or somatotropin injections or, (3) no treatment. Comparisons of weights, progesterone content, and cell types of these corpora lutea revealed that bovine STH (75 mg./day), ovine prolactin (1704 I.U. units/day), and two levels of equine LH (20 and 100 mg./day) were not luteotropic, since they did not overcome oxytocin inhibition. The means of total progesterone level in the corpora of six STH-treated heifers, five prolactin-treated heifers, and four low and five high level LH-treated heifers were 82 mcg., 21 mcg. 32 mcg., and 11 mcg., respectively. An average of 28 mcg. of total progesterone was found in corpora from heifers treated with oxytocin alone. In contrast five heifers receiving HCG (2000 IU/day) and five receiving a crude bovine AP extract (3.5 gland equivalent/day) produced corpora having mean total progesterone contents of 608 and 363 mcg., respectively. An average of 261 mcg. of total progesterone was found in corpora of untreated heifers. The results suggest that there is a specific luteotropic hormone in the bovine, and that it is not bovine STH, equine LH or ovine prolactin.

Maintenance of Pregnancy in Ovariectomized Cattle with Progestin Compounds and Their Effect on Progestin Levels in the Corpus Luteum ,

Summary Bilateral ovariectomy was performed on 22 dairy animals at 55–143 days of pregnancy. Exogenous progesterone in the form of Delalutin (17-alpha-hydroxy-progesterone-17-n-caproate) and repositol progesterone (progesterone in propylene glycol) was administered at various dosage levels and time intervals to try to maintain pregnancy. Pregnancy was maintained following ovariectomy after 88 days with daily injections of 125mg of Delalutin when the treatment was started at least eight days before surgery. Daily injections of 50mg of repositol progesterone beginning 0–12 days before ovariectomy maintained pregnancy after the 66th day. Smaller daily injections of either repositol progesterone or Delalutin were more satisfactory in maintaining pregnancy than larger, less frequent injections. Neither repositol progesterone nor Delalutin maintained pregnancy when 500mg were injected weekly. When repositol progesterone was withdrawn more than six days before parturition (expected at 279 days), the placentae were retained in all cases and were very difficult to remove 48 to 60 hr later. When repositol progesterone or Delalutin was withdrawn at 274–278 days, normal parturition occurred in two to six days. Total progesterone and its concentration in the corpus luteum was significantly increased (P 4 -pregnene-20- β -ol-3-one was unaffected, being slightly higher in the untreated cows. There was also a consistent increase in progesterone concentration in the ovaries minus the corpus luteum for the treated cows, as compared with untreated cows (P