Peripheral Plasma Progesterone Levels Research Articles

Study of progesterone level during first trimester of pregnancy in cows.

Measurement of progesterone is an indirect method for pregnancy diagnosis in many livestock species including cattle, buffaloes, sheep, and goats. Conception extends the life of the corpus luteum (CL) by preventing the luteolytic mechanism from being triggered, thus prolonging and maintaining its functional characteristics, ensuring continued high progesterone levels (Spencer, et.al., 1995). (Shemesh et al., 1973) proposed that the difference in peripheral plasma progesterone levels between pregnant and non pregnant cows, 19 days after insemination, can form the basis for a very early pregnancy test. (Laing and Heap 1972) first documented this in milk to diagnose cows in early pregnancy Progesterone maintains the uterine endometrium in a state which supports embryonic development, implantation, and foetoplacental development. Progesterone concentrations vary with the stage of the estrous cycle which makes it one of the most commonly studied reproductive hormones in bovine ruminants for pregnancy detection and ovarian activity (Kaneko,et.al.,1994). Studies in the bovine estrous cycle indicate that the milk or serum progesterone concentrations reach a maximum value 13-14 days after estrus, and if the animal is pregnant, these continue to remain elevated up to day 21 after fertilization (Parkinson, et al.,1994) . These high levels of progesterone in serum or milk between days 18 and 24 after insemination form the basis of establishment of pregnancy in cattle (Sasser, and Ruder,1987; Shemesh,1973). Interferon-???? exerts its antiluteolytic effect by inhibiting the endometrial expression of oxytocin receptors, through which oxytocin stimulates pulsatile PGF2???? release (Wolf,2003). Although low progesterone concentrations at 18 to 24 days after breeding can accurately predict non pregnancy, high progesterone concentrations during this period are not the specific indicators of pregnancy due to variations among cows in duration of the estrous cycle as well as the incidence of early or late embryonic mortality. The advantages of progesterone assay for pregnancy diagnosis include noninvasive collection of milk sample and the feasibility to conduct the test on the farm using commercial cow-side milk progesterone test kits [Pennington,1985 ; Gowan,1982 ; Wimpy,et.al.,1986), though the sensitivity gets compromised to some extent with these assay kits.
 Key Word: progesterone, pregnancy, cows

Ultrasound image analysis offers the opportunity to predict plasma progesterone concentrations in the estrous cycle in cows: A feasibility study

In recent years, several attempts have been made to evaluate the activity of a corpus luteum by determining its sonographic echo texture. In all of these studies the values of the echo texture parameters depended on the type and settings of the ultrasound machine. Therefore, the aim of the study was to investigate if a quantitative analysis of ultrasound (US) images of the corpus luteum (CL) after calibration of the ultrasound machine enables the assessment of the peripheral plasma progesterone (P4) level. Ten Holstein Friesian cows were examined daily at Days 4 to 8, 10 to 16, and −5 to −1 (Day 1 = ovulation) of the estrous cycle. B-mode sonography of the corpora lutea was performed and blood samples were taken for plasma P4 analysis. US images were calibrated and analyzed using a software package (CAUS) developed by the authors. In addition to the area of the CL (Total Area, TotA; Tissue Area interactive, TisAi; Tissue Area Automatic, TisAa), the following US parameters were calculated from the gray level histogram and from the size of the speckles: Mean, Standard Deviation (SD) and Signal-to-Noise Ratio (SNR = Mean/SD) of echo levels, Residual Attenuation (ResAtt), Axial and Lateral speckle size (Ax and Lat, respectively). The inter-individual variability of the P4 level was expressed by the coefficient of variability (CV), averaged over all days. It appeared that the CV of the absolute P4 was high (0.65) and the P4 relative to that at Day 4 and at Day 16 was of comparable magnitude. Correlations of US parameters with P4 were highest for the P4 relative to Day 16 (P4_rel_D16). This relative P4 measure was then used for further analysis. The correlations of P4_rel_D16 with TotA, TisAa (CL area after automatic segmentation of tissue) and ResAtt were found the highest ( R = 0.68, 0.74, and −0.42, respectively). Multiple linear regression analysis, incorporating all US parameters revealed the formula: P4_rel_D16 pred = −0.315 + 0.225TisAa − 0.023ResAtt , and a goodness of fit: R 2 = 0.59 ( p < 0.001). This formula was then used to “predict” for each image the P4_rel_D16 from the estimated US parameters. A high correlation of the predicted with the measured P4_rel_D16 was found: R = 0.77. Classification of images using the predicted P4_rel_D16 to be in the range >0.80 (corresponding to 0.95 times the average_P4_rel_D16 measured during the “static” phase of the luteal cycle) by ROC analysis was correctly made in 88% of cases. In conclusion the quantitative analysis of calibrated ultrasound images may yield a good prediction of cyclic changes of P4 levels and has potential for predicting the phase in the estrous cycle of a cow.

Relationship between Ultrasonographic Assessment of the Corpus Luteum and Plasma Progesterone Concentration during the Oestrous Cycle in Monovular Ewes

ContentsUltrasonographic observations of the corpus luteum (CL) and collection of blood samples for progesterone radioimmunoassay were performed daily during 15 oestrous cycles in Spanish Merino ewes, a consistently monovular breed. Ultrasonographic image of the CL changed during the oestrous cycle, increasing its echogenic pattern from ovulation to luteolysis. The size of the CL and mean progesterone levels were significantly affected by day of cycle (p &lt; 0.05 and p &lt; 0.001, respectively). Both increased their values from day 1 to day 12 (from 49.6 ± 7.4 to 154.6 ± 11.8 mm2 and from 0.2 ± 0.0 to 2.8 ± 0.5 ng/ml, respectively) and then declined sharply until day 0 (28.2 ± 5.3 mm2 and 0.1 ± 0.0 ng/ml, respectively). There was a significant correlation between CL area and plasma progesterone concentrations during the entire oestrous cycle, taking the developing and regressing phases of the CL separately (p &lt; 0.05). A central cavity was observed in 33.3% of the CL studied. The presence of this cavity had no effect in total luteal‐tissue area of the CL nor on oestrous cycle length or on progesterone concentrations. Likewise, the cavity did not affect the correlations observed between CL size and progesterone levels, CL size and day of cycle and progesterone levels and day of cycle. It is concluded that ultrasonographic assessment of CL area is a reliable method for estimating peripheral plasma progesterone levels, regardless to the presence or absence of a cavity in the CL.

Intrauterine and intravaginal insemination with frozen canine semen using an extender consisting of orvus ES paste-supplemented egg yolk tris-fructose citrate.

Our previous report indicated that addition of Orvus ES Paste (OEP) to the extender of frozen canine semen protected acrosomes and maintained sperm motility after thawing. In this study, artificial insemination (AI) using the frozen semen was carried out. The frozen semen was prepared using egg yolk Tris-fructose citrate, and the final concentrations of glycerol and OEP were 7% (v/v) and 0.75% (v/v), respectively. AI was performed during the optimal mating period predicted from the peripheral plasma progesterone level. In intrauterine insemination (IUI), the bitches were laparotomized and 1 x 10(8) spermatozoa were infused into one of the uterine horns. In insemination of non-OEP supplemented semen, 3 x 10(8) spermatozoa were inseminated. In intravaginal insemination (IVI), 10-40 x 10(8) spermatozoa were inseminated. Conception was obtained in nine of 10 bitches (90.0%) that underwent IUI. The number of newborns was from 1 to 7 (mean 3.6 +/- 0.9). The mean ratio of the number of puppies to the number of ovulations in the inseminated uterine horn was 71.8%. The number of puppies did not exceed the number of ovulation in the inseminated uterine horn. Conception using non-OEP supplemented frozen semen was unsuccessful in all four bitches. In IVI, conception was not obtained in any of the six bitches that received insemination of 10 x 10(8) or 40 x 10(8) spermatozoa, but two of three bitches that received insemination of 20 x 10(8) spermatozoa were fertilized. It was shown that a high conception rate can be obtained by IUI using OEP-supplemented frozen canine semen. Developmenmt of a non-surgical method of IUI and a method of freezing canine sperm applicable to IVI is necessary.

Reproductive biology of the brush‐tailed phascogale, Phascogale tapoatafa (Marsupialia: Dasyuridae)

AbstractThis study investigated the reproductive biology of a captive population of brush‐tailed phascogales Phascogale tapoatafa. A ‘round robin’ mating system was established in which seven adult male animals were rotated through seven adult females. Changes in vaginal cytology and peripheral plasma progesterone and oestradiol levels were monitored to determine features of the female reproductive cycle. Regular measurement of scrotal diameter, collection of testicular biopsies and monitoring of plasma testosterone levels was used to assess male reproductive activity. Oestrous cycle length was estimated as 40 ± 5 days (n= 7) and gestation length as 27 ± 5 days (n= 7). Plasma progesterone levels showed no significant variation. This negative result is attributed to the small sample size (n= 4). Plasma oestradiol levels however, followed the predicted pattern, with an increase in peripheral concentration occurring prior to the breeding season. Oestradiol concentration peaked at 246.9 ± 169.2 pg ml−1 (mean ±se) just before mating and declined to 24.3 ± 12.0 pg ml−1 after mating. Histological studies of testicular biopsies revealed that spermatogenesis does not cease until after the breeding season has begun, in contrast to Antechinus species, in which spermatogenesis ceases before breeding. Plasma testosterone levels increased at the onset of the breeding season, peaking at 6.3 ± 0.60 ng ml−1. Testosterone concentrations remained high until approximately 3 weeks after breeding, followed by a decline to pre‐breeding levels. Litter size and sex ratio did not vary significantly between first‐ and second‐year females. Females did not undergo a second oestrous cycle when pouch young were removed 15 and 17 days after parturition.

Peripheral plasma oestradiol-17β and progesterone levels in female goats induced to hypothyroidism

Subcutaneous injections of thiourea were given to five mature female goats, initially at the rate of 100 mg kg −1 body weight per day for 15 days and then at 66.7 mg kg −1 body weight per day for the following 15 days. Triiodothyronine (T3) and thyroxine (T4) plasma levels were reduced during the period of thiourea treatment. This confirmed successful induction of hypothyroidism. Behavioural oestrus was exhibited by three animals on day 22, and by two animals on day 23 of thiourea treatment, whereas in the control group oestrus was observed on days 19–20. The symptoms of behavioural oestrus in treated females were partially suppressed; however, the duration of oestrus was 48–50 h compared with 36–48 h in control animals. Plasma oestradiol-17β and progesterone levels during the oestrous cycle in thiourea-treated goats were lower ( P < 0.05) than in control animals and when artificially inseminated, treated goats did not conceive. The results of this experiment confirm the hypothesis that the thyroid is involved in maintenance of the reproductive process.

An attempt to use progesterone treated XO mares as embryo recipients

SummaryXO mares were evaluated as potential embryo transfer recipients. In the first part of the study, they were treated with oestrogen and progesterone for 10 and 14 consecutive days. During this course of steriod treatment, their endometria changed in histological appearance from anoestrous to dioestrous and their peripheral plasma progesterone levels rose from below 0.3 ng/ml to above 2 ng/ml. Plasma LH concentrations also rose during the period of oestrogen administration but declined again to baseline when progesterone treatment began. Urinary oestrogen concentrations rose and fell in conjunction with oestrogen treatment. In the second part of the study 16 Day 7 embryos were transferred non‐surgically to seven XO mares given daily injections of progesterone and 12 embryos were transferred to eight ovariectomised mares treated similarly with progesterone. Pregnancies were established in five of the ovariectomised mares but not in any of the XO mares. The possible reasons for the failure to establish pregnancy in the XO mares are discussed.

Effects of unilateral ovariectomy before mating on pregnancy in rabbits.

The effects of unilateral ovariectomy (ULO) before mating on maintenance of pregnancy, plasma progesterone levels and ovarian hypertrophy were examined using adult rabbits. The values related to reproductive efficiency, such as number of ovulations and implantation sites, implantation rates, size of uterine swellings, litter size, weight of young, birth rate, duration of pregnancy and peripheral plasma progesterone levels per doe, did not show any significant differences between ULO and intact does. The mean ovarian weight and the volume of ovaries after the second parturition in ULO and intact does became slightly larger than those of ovaries after the first parturition, though no significant differences were noticed between the first and the second. The ovarian weight and volume of ULO does after the second parturition was significantly larger than those of removed ones at ULO (p<0.05). These results suggest that ULO before mating did not affect the maintenance of pregnancy, fetal growth and litter size by the compensatory function of the remaining ovary in the ULO animal.

Peripheral plasma prolactin and progesterone levels in pseudopregnant goats during bromocryptine treatment

Persistence of luteal function and accumulation of fluid within the uterus (hydrometra) are characteristics of pseudopregnancy in goats. To study the luteotrophic role of prolactin in this condition, seven seudopregnant goats were treated with bromocryptine (1 mg subcutaneously, twice daily) for 6 to 10 d. Plasma progesterone (P4) and prolactin (PRL) were measured by radioimmunoassay (RIA) in samples taken twice daily by venipuncture. Ultrasound scanning took place at regular intervals to visualize the presence of fluid within the uterus. Bromocryptine treatment effectively reduced the plasma PRL concentration in six goats. In all seven goats, a gradual decrease of the plasma P4 concentration to levels < 1.8 ng/ml occured during treatment. After bromocryptine treatment, P4 concentrations reached basal levels (<0.1 ng/ml) in two animals. In four goats, P4 concentrations remained close to 1.0 ng/ml, or even temporarily rose above the 2.0 ng/ml level. Spontaneous discharge of uterine fluid took place during (two goats) or within 4 d after bromocryptine treatment (three goats). These results indicate that prolactin plays an important luteotrophic role during pseudopregnancy in goats.

Clinical and endocrine studies in mares with known history of repeated conceptus losses

Six mares which had lost their conceptuses two to five times during the last six years were used in a study extending over one breeding season. The genital organs were examined by palpation per rectum, ultrasound scanning and vaginoscopy. Cytological, bacteriological and histological examinations of the endometrium were carried out before mating. Blood samples were collected twice daily beginning one estrous cycle before mating until Day 150 of pregnancy. Radioimunoassay systems were used to determine peripheral plasma levels of progesterone, equine chorionic gonadotropin and estrone sulphate. One mare had persistent acute endometritis and was treated before mating. All six mares conceived and five mares had normal pregnancies with live fetuses at the end of the experimental period. One mare aborted, the fetus died around Day 50 of pregnancy and remained intact in the uterus for two months. This mare had the same high levels of progesterone (p) as the other mares until shortly before abortion. The production of equine chorionic gonadotropin (eCG) was relatively low compared with the mares with live fetuses, and estrone sulphate concentrations were significantly lower from Day 61 of pregnancy. Several reasons might have caused the good breeding results of the mares during this trial, but management seems to be the most important factor.

Investigations on endocrine responses in the bitch following hysterectomy

In most domestic species (e.g. cattle, sheep) prostaglandin F2α of endometrial origin is considered to be the active principle leading to luteolysis at the end of the estrous cycle; hence in these species hysterectomy leads to the formation of a persistent corpus luteum, the application of PgF2α induces luteolysis. Data for the bitch are conflicting; while exogenous application of PgF2α or analog acting compounds can lead to a decline in peripheral plasma progesterone levels [1], hysterectomy during the on-going cycle apparently does not lead to early luteal regression [2]. In order to obtain further information, a long-term study was designed of hysterectomized bitches and an equal number of control animals.

Peripheral plasma levels of progesterone in Nigerian Zebu cows following synchronization of oestrus with Prostaglandin F 2 alpha analogue (dinoprost tromethamine)

The luteolytic effect of Prostaglandin F 2 alpha (PGF 2α) was studied by measuring plasma progesterone levels in 30 Bunaji and Sokoto Gudali (Zebu) cows. Two intramuscular (i.m.) injections each of 25 mg of the analogue (Dinoprost tremethamine) were given 11 days apart and blood samples for plasma were collected daily beginning from first injection up to 7 days after the second injection of PGF 2α or up to 30 days after artificial insemination (A.I). Mean progesterone levels on the day of first injection were 4·1 + 0·3 and 0·6 ± 0·2 nanograms per millilitre (ng/ml) for cows in luteal and follicular phases respectively. Luteolysis was complete within 24–48 h of injection as confirmed by plasma progesterone levels. Cows in luteal and follicular phases showed standing oestrus 75·1 ± 2·1 h and 55·2 ± 12·2 h after PGF 2α injection. Partial or incomplete luteolysis were also observed in 2 cows. Cows showing standing oestrus after a second injection of PGF 2α were artificially inseminated 12 h after the onset of oestrus. Six out of 12 cows (50%) were diagnosed pregnant by rectal palpation at 60 days post-insemination. Plasma progesterone levels in pregnant cows remained elevated (2–15 ng/ml) and did not drop below 2·0 ng/ml following attainment of peak levels. Appreciable levels (1.0 ng/ml) of progesterone were first detected 5–6 days postinsemination in inseminated cows. Of those that were later diagnosed non-pregnant, however, there was a cyclic progesterone pattern which culminated in complete luteolysis about 18 days after the infertile insemination. The results indicate that intramuscular administration of 25 mg of PGF 2α per cow during the luteal phase of the oestrous cycle of Zebu cows shortens the secretory lifespan of cyclic corpus luteum, and that plasma progesterone assays may be valuable in assessing the reproductive performance of Zebu cows indigenous to Nigeria.

Plasma progesterone and prolactin changes in superovulated women before, during, and immediately after laparoscopy for in vitro fertilization and their relation to pregnancy

To define changes in peripheral plasma progesterone (P) and prolactin (PRL) levels in relation to oocyte recovery for in vitro fertilization (IVF), the authors studied these hormones in 20 women before, during, and after oocyte recovery for IVF. The patients were superovulated with clomiphene citrate and human menopausal gonadotropin and underwent general anesthesia (19 women) or epidural anesthesia (1 woman) and laparoscopy for follicular aspiration. One half of the women were given bromocriptine to control PRL levels during anesthesia. There was a marked drop in P levels (mean decrease of 76%) within the 2 hours after induction of anesthesia and follicular aspiration. PRL levels rapidly rose in patients not treated with bromocriptine. Four of the 20 patients became pregnant after embryo transfer, and in these women P levels were significantly higher than in nonpregnant patients before and during oocyte recovery. Changes in PRL levels and P levels during oocyte retrieval were not related to the occurrence of pregnancy.

Effects of furazolidone on some reproductive hormones during oestrous cycle in the goat

1. In non-pregnant goat luteolysis is characterized by a decline in peripheral plasma progesterone level and increased peripheral plasma concentrations of testosterone (T) and 5 α-dihydrotesosterone (DHT). 2. Daily oral doses of furazolidone (80 mg/kg) between days 10 and 16 delayed luteolysis and suppressed both the decline in progesterone concentrations and the increase in T and DHT level.

Use of deuterium-labelled tracers to establish endogenous rates of production and clearance of progesterone during the peri-implantation period in gilts

Using a method based on the constant infusion of a deuterium-labelled tracer, production rates (PR) and metabolic clearance rates (MCR) of progesterone have been determined in gilts between Days 11 and 17 of gestation. This involved the development of a procedure to quantitate the tracer [(7,7,16- 2H 3)-progesterone] in plasma samples, and in the infusate, with the aid of gas chromatography-mass spectrometry. In a group of nine mated gilts, the average (± s.e.m.) progesterone PR was 274 (± 26) μmol/24 h, the average progesterone MCR being 3348 (± 312) 1 24 h . Declining peripheral plasma progesterone levels (PP) between Days 11 and 17 of gestation were associated with increasing progesterone MCR ( P < 0.05), and were not correlated with increasing PR. For comparison, progesterone PRs and MCRs were determined in five unmated gilts between Days 11 and 15 of oestrus, prior to the normal onset of luteolysis. The mean progesterone MCR in these animals (2735±275 1 24 h ) was similar to the respective pregnancy mean ( P > 0.1), but the PR (158±12 μmol/24 h) was lower ( P < 0.01). PP values, PR values and numbers of corpora lutea were not significantly correlated ( P > 0.1) in either mated or unmated groups of gilts. The results of this study support previous indications of luteotrophic effects of conceptus tissues after Day 10 of pregnancy in the sow, and provide quantitative bases for progesterone replacement in ovariectomized pigs between Days 11 and 17 after oestrus/coitus.

Clinical and Endocrinological Studies in Primiparous Post Partum Sows Effects of Lactation Length and Litter Size By

The object of this investigation was to determine the relationships between clinical findings and hormonal patterns in primiparous sows with different lactation length and litter size during lactation, weaning and to the first oestrus. Seven pairs of primiparous full sib sows were used to determine the effect of lactation length with normal litter size. One sow of each pair was assigned to nurse the piglets for 3 weeks (group A) while the other nusred for 5 weeks (group B). Another 8 primiparous sows (group C) were assigned to nurse 2–4 piglets during a 5-week lactation period. Oestrus detection was performed twice daily and laparoscopic examination every 2 weeks. If the sows did not come in oestrus within 3 weeks after weaning they were slaughtered. Peripheral plasma levels of progesterone, oestradiol-17β and LH were estimated by radioimmunoassays throughout the experimental period.

Plasma progesterone in the umbilical vessels at term--an overview.

This paper reports the results of umbilical cord vein and artery, and maternal peripheral vein plasma progesterone levels in over 300 term human deliveries, individual aspects of which have previously been reported. An attempt was made to assess the fetal status objectively, and the results confirm that cord progesterone levels are correlated with the mode of delivery, the clinical indications for the mode of delivery and the clinical condition of the fetus after delivery. No relation was found to fetal sex, induction of labour or maternal antenatal complications.

The acute effect of placentectomy and hysterectomy on peripheral plasma progesterone levels and ovarian progesterone secretion in the pregnant rat.

The role of placental luteotrophins in modulating plasma progesterone concentrations and ovarian progesterone secretion was examined in 16-day pregnant rats. In an initial experiment rats were placentectomized and their plasma progesterone concentrations monitored for 24 h; the rats were conscious within 30 min of placentectomy. Relative to control values, progesterone concentrations fell significantly within 0.5 h. A venous outflow technique was then used to monitor rates of progesterone secretion from ovaries of hysterectomized and control rats maintained under anaesthesia. Hysterectomy had no apparent effect on either progesterone secretion or plasma progesterone concentrations for at least 2 h. A final experiment was carried out to compare the effects of hysterectomy on plasma progesterone concentrations in conscious rats with those of placentectomized rats of the first experiment. Progesterone concentrations did not change significantly in hysterectomized rats for 4 h but fell to very low values by 24 h. These results suggest that placental luteotrophins do not have an acute, direct role in the control of plasma progesterone levels but are needed to maintain progesterone secretion in the longer term and possibly inhibit uterine luteolysin release.

The effect of estrogen antagonism on progesterone production in early pregnancy in the baboon (Papio cynocephalus)

These studies were designed to investigate the role of estrogen on progesterone production in early pregnancy in the baboon, when the contribution of the corpus luteum and placenta has not been established. Oral administration of the estrogen antagonist MER-25 at two dosage levels (15 and 30 mg/kg/day) to the pregnant baboon from days 35 to 55 after conception results in a decline in peripheral plasma levels of progesterone within a few days and persists for at least 20 days after the termination of treatment with no effect on plasma estradiol levels. The same study was done with the use of a different estrogen antagonist, trioxifene mesylate (5 mg/kg/day), and there was no effect on plasma progesterone, although a transient depression in plasma estradiol was evident. These actions may be due to an inherent estrogenicity of trioxifene. In preliminary studies an effect of these estrogen antagonists on placental size and morphology has been observed. Estrogen deprivation in early pregnancy of the baboon results in a depression in plasma progesterone and indicates a placental requirement for estrogen in progesterone product at this stage of pregnancy.

Changes of PGFs and progesterone levels in peripheral plasma of the shiba-goats after administration of PGF&lt;SUB&gt;2α&lt;/SUB&gt;.

Changes of PGFs and progesterone levels in peripheral plasma of the shiba-goats after administration of PGF&lt;SUB&gt;2α&lt;/SUB&gt;.