Mean Progesterone Concentrations Research Articles

Follicular and steroid hormone changes in Arabian mares in the postpartum period

In this study, the aim has been to characterize the profiles of progesterone, estradiol and follicular changes during postpartum period from parturition to first postpartum ovulation. Jugular venous blood was taken daily for progesterone and estradiol assay until first postpartum ovulation. The diameters of the follicles of the ovaries were recorded. The mean progesterone and estrogen concentrations markedly decreased ( p < 0.05) during the 48 h after parturition. No correlation was observed between estradiol concentrations and the diameter of the largest follicle whereas a negative correlation was present between the number of follicles smaller than 20 mm and the number of follicles larger than 20 mm on the third and fourth days after postpartum.

The effect of oxytocin and PGF 2α on the uterine involution and pregnancy rates in postpartum Arabian mares

In this study, the effects of oxytocin and an analog of prostaglandin (cloprostenol) on the uterine involution and pregnancy rates were investigated. Mares received 3 ml of 0.9% NaCl in Group C ( n = 10), 30 IU/mare of oxytocin in Group O ( n = 10) and 250 μg/mare of cloprostenol in Group P ( n = 10) within 12 h after parturition. The gravid uterine horn's cross-sectional diameter was measured by ultrasonography. The mean uterine diameters did not differ significantly between the treatment (O and P) and the control (C) groups ( p > 0.05). The difference between the postpartum ovulation periods (Group C: 12.6 ± 0.72 days, Group O: 15 ± 1.33 days, Group P: 14.6 ± 1.11 days), the pregnancy rates at foal heat (Group C: 60%, Group O: 60%, Group P: 80%) and the embryonic death rates at foal heat (Group C: 33.3%, Group O: 16%, Group P: 25%) were not found to be statistically significant between the treatment and the control groups. The mean progesterone concentrations were similiar in all groups and decreased continuously from parturition to until foal heat (Group C: from 2.43 ± 0.24 to 0.66 ng/ml, Group O: from 3.07 ± 0.6 to 0.27 ± 0.27 ng/ml and Group P: from 2.8 ± 0.44 to 0 ng/ml) ( p > 0.05). In conclusion, it was decided that the oxytocin and PGF 2α treatments performed on the mares with the purpose of stimulating involution had no effect on the duration of parturition–first ovulation, the shrinkage of the uterus diameter, the pregnancy and embryonic death rates.

Effect of embryo source and recipient progesterone environment on embryo development in cattle

The aim of the present study was to examine the effect of embryo source (in vivo v. in vitro) and the progesterone environment into which it was transferred on Day 7 on embryo survival and size on Day 13. Day 7 blastocysts were produced either in vivo using superovulation, artificial insemination and non-surgical embryo recovery or in vitro using in vitro maturation, fertilisation and culture. In order to produce animals with divergent progesterone concentrations, following synchronisation recipients were either superovulated (High progesterone; n = 10) or not (Control progesterone; n = 10). Ten blastocysts, produced either in vivo or in vitro, were transferred to each recipient on Day 7. Both groups were killed on Day 13. The mean progesterone concentration from Day 7 to Day 13 (the period when the embryos were in the uterus) in the High and Control progesterone recipients was 36.32 +/- 1.28 and 10.30 +/- 0.51 ng mL(-1), respectively. Of the in vivo embryos transferred, the overall recovery rate at Day 13 was 64%, which was higher (P < 0.001) than that of 20% for the in vitro embryos transferred. The mean area of embryos recovered from High progesterone recipients was 3.86 +/- 0.45 mm(2) (n = 28) compared with 1.66 +/- 0.38 mm(2) (n = 24) for embryos recovered from Control progesterone recipients (P < 0.001). Similarly, the origin of the embryo used for transfer affected embryo size on Day 13. In summary, the recovery rate of blastocysts was higher for in vivo- than in vitro-derived embryos. Blastocyst size was approximately 2.3-fold greater in recipients with high compared with normal progesterone. The present study lends strong support to the hypothesis that an earlier rise in progesterone after conception stimulates blastocyst growth and the development of competent embryos.

The effects of GnRH analogue (buserelin) or hCG (Chorulon) on Day 12 of pregnancy on ovarian function, plasma hormone concentrations, conceptus growth and placentation in ewes and ewe lambs

The objectives of this study were to determine the effect of GnRH analogue (buserelin) or human chorionic gonadotrophin (hCG, Chorulon) treatment on Day 12 of pregnancy on ovarian function, plasma hormone concentrations, conceptus growth and placentation in ewes and ewe lambs. After oestrus synchronization with progestagen sponges and eCG, all the animals were mated with fertile rams. Both ewes and ewe lambs (20 per treatment group) were given either normal saline or 4 μg GnRH or 200 IU hCG on Day 12 post-mating. Pre- and post-treatment plasma hormone concentrations were determined in seven pregnant animals per treatment group in samples collected 1 h before and 0, 2, 4, 6, 8, 24, 48 and 72 h after treatment. Overall mean progesterone concentrations were higher ( P < 0.001) in ewes as compared with ewe lambs in saline-treated controls. GnRH or hCG treatment increased ( P < 0.001) mean plasma progesterone concentrations in both age groups, however, post-treatment concentrations were significantly ( P < 0.05) higher in ewes than in ewe lambs. Oestradiol concentrations were similar in the two control groups. In ewes, but not in ewe lambs, both GnRH and hCG treatments significantly ( P < 0.05) increased the mean oestradiol concentrations above pre-treatment levels. Moreover, post-treatment oestradiol concentrations in GnRH- and hCG-treated animals were significantly ( P < 0.05) higher than those in the saline-treated controls. LH release in response to GnRH treatment was greater ( P < 0.05) in ewes than in ewe lambs, whereas FSH release in ewes was less ( P < 0.05) than that of ewe lambs. The effects of GnRH or hCG on conceptus growth and placentation was determined at slaughter on Day 25. In ewes, GnRH treatment increased ( P < 0.05) luteal weight, amniotic sac width and length, and crown-rump length compared with controls, but had no effect on these parameters in ewe lambs. In ewes, hCG treatment also enhanced ( P < 0.05) luteal weight, amniotic sac width and length, crown-rump length, embryo weight and number of placentomes as compared with controls. In ewe lambs, there was no difference ( P < 0.05) between hCG and control groups in luteal weight, embryo weight and amniotic sac width but crown-rump length, amniotic sac length and the number of placentomes forming the placenta were greater ( P < 0.05). In conclusion, GnRH or hCG treatment on Day 12 of pregnancy can increase ovarian function, conceptus growth and placental attachment in ewes. However, these treatments were less effective in ewe lambs.

Detection of fetal gender differences in maternal serum progesterone concentrations of Asian elephants ( Elephas maximus)

Previous studies have analyzed total testosterone concentrations in maternal serum for a reliable method of fetal gender determination in Asian elephants ( Elephas maximus). The present study investigated the possibility that progesterone concentrations in maternal serum may reflect these testosterone patterns. Weekly serum samples were collected from 17 pregnancies in captive Asian elephants and analyzed via radioimmunioassy (RIA) for progesterone concentrations. Nine and eight cows carried male and female calves, respectively. Mean progesterone concentrations in maternal serum of elephants carrying male calves were greater than in those carrying female calves ( P < 0.01). Mean progesterone concentrations (based on 5-week means) in maternal serum were greater at weeks 20–55 ( P < 0.01) and 60–65 ( P < 0.05) for elephants carrying male calves.

Pregnancy rates, LH and progesterone concentrations in mares treated with a GnRH agonist

The aim of the study was to investigate the effect of the GnRH agonist Buserelin given on day 10 after ovulation on pregnancy rate and concentrations of progesterone and LH. Altogether 191 warmblood mares were used for two trials. Fresh or frozen/thawed semen from 27 stallions was used for A.I. In trial A 171 mares received either Buserelin (Receptal ®, Hoechst, Germany, 40 μg/animal) or 10 ml 0.9% NaCl (placebo). On day 16 after A.I. pregnancy diagnosis was performed by ultrasound scanning of the uterus. For statistical analysis, data were analyzed by a mixed model, with four fixed factors (treatment, type of spermatozoa, A.I. number, reproductive status of the mare) and a random factor (stallion). Least Square Means (LSM) for pregnancy rate were 46.0% in GnRH agonist treated mares and 36.4% in the control group ( P = 0.22). In trial B 20 lactating and cycling mares were used for endocrine studies. Blood samples were recovered for analyses of progesterone and LH from days 0 to 11. The mean progesterone concentrations increased continuously from days 0 to 8 after ovulation in both groups (GnRH group: from 0.81 ± 0.48 to 5.47 ± 0.48 ng/ml, control group: from 0.63 ± 0.68 to 5.83 ± 0.68 ng/ml). Moreover, the progesterone concentrations from days 9 to 11 were not different between the GnRH and the control group. In contrast to this LH concentrations were markedly influenced by the GnRH agonist. On day 10 LH concentrations were significantly higher in GnRH agonist treated than in placebo treated animals. From the data obtained from individual animals it can be concluded that GnRH agonist, given during luteal phase may have different effect on luteal function.

Computer assisted image analyses of corpora lutea in relation to peripheral concentrations of progesterone: A comparison between breeds of sheep with different ovulation rates

Transrectal ovarian ultrasonography is a non-invasive technique that permits the real-time serial visualization of ovarian structures. Previous studies have reported correlations between serum progesterone concentrations and physical characteristics of the corpus luteum (CL) in different species. The aim of the present study was to investigate whether or not there were correlations between ultrasound image attributes of the CL and changing progesterone concentrations over time, in prolific and non-prolific ewes. Ultrasonographic images of CL were taken, once daily, from 12 Western White Face ewes and 7 Finn ewes for the duration of one luteal phase. Blood samples were collected daily prior to each scanning session and assayed to determine mean serum concentrations of progesterone. Analysis of ultrasound images was performed using a series of custom-developed computer algorithms optimized for ultrasonography on a computer graphics workstation. Both total luteal area and mean pixel values were correlated with the pattern of serum concentrations of progesterone from days 3 to 15 after ovulation in Western White Face ewes and from days 3 to 14 in Finn ewes. There was no significant correlation between progesterone concentrations and spot pixel heterogeneity for either Western White Face ewes or Finn ewes. We concluded that pixel heterogeneity is a poor indicator of progesterone secretory ability of the CL when compared to mean pixel values. However, luteal area and mean spot pixel values are better but not strong indicators of the functional status of the CL in cyclic ewes.

16 PROGESTERONE RELEASE PATTERNS FROM CUE-MATE IN COMPARISON TO OTHER INTRAVAGINAL PROGESTERONE-RELEASING DEVICES IN LACTATING DAIRY COWS

Various intravaginal progesterone-releasing devices are commercially available and each is impregnated with different amounts of progesterone. An experiment was designed to characterize plasma progesterone release profiles from Cue-Mate in comparison with other commercially available progesterone-releasing devices. Cycling, lactating Holstein cows (n = 60; BCS between 2.0 and 3.0 out of 5) from commercial dairy farms in Argentina were used in 2 replicates. All cows received 2 injections of D+ cloprostenol (PGF, Bioprost-D�; Biotay, Buenos Aires, Argentina) 14 days apart and were randomly assigned to one of four groups to receive intravaginal devices as follows: Cue-Mate (1.56 g progesterone; Bioniche Animal Health, A/Asia Pty, Armidale, Australia; n = 10), DIB (1 g progesterone; Syntex SA, Argentina; n = 10), CIDR with 1.9 g progesterone (Pfizer Salud Animal S.A., Buenos Aires, Argentina; n = 10), or CIDR with 1.38 g progesterone (Pfizer Animal Health, Groton, CT, USA; n = 10). All devices were inserted 24 hours after the second PGF and were left in place for 31 days. Blood samples were taken for progesterone analysis at 6-hour intervals for the first 24 hours, then daily for a week, and every 2 days for an additional 25 days. Plasma progesterone concentrations were measured with a modified human double-antibody RIA kit (DPC Coat-A-Count�; Diagnostic Products Corporation, Los Angeles, CA, USA). Cows were observed twice daily to confirm that vaginal inserts were still in place. Time-series hormone data were analyzed using the MIXED procedure for repeated measures (SAS Institute, Inc., Cary, NC, USA). Main effects of device and time, the highest mean concentration of progesterone, and the mean day on which this occurred were compared by a protected LSD test. There was no evidence of cow discomfort with any of the vaginal devices, and loss rates did not differ. There was an effect of group (P &amp;lt; 0.001) and day (P &amp;lt; 0.001) for progesterone concentrations, but there was no interaction (P = 0.89). Peak concentrations of progesterone (ng mL-1) did not differ among groups (Cue-Mate: 5.0 � 1.1; DIB: 3.9 � 0.6; 1.9-g CIDR: 4.6 � 0.6; 1.38-g CIDR: 3.7 � 0.4; P = 0.51). Mean (� SEM) concentrations of progesterone over the 31-day insertion period differed between 1.9-g CIDR (1.8 � 0.2 ng mL-1) and DIB (1.5 � 0.1 ng mL-1, P &amp;lt; 0.006), with Cue-Mate (1.5 � 0.2 ng mL-1) and 1.38-g CIDR (1.6 � 0.1 ng mL-1) intermediate and not different from either. When data were evaluated from insertion until Day 7, mean plasma progesterone concentrations did not differ among groups (Cue-Mate: 2.2 � 0.2 ng mL-1; DIB: 2.2 � 0.1 ng mL-1; 1.9-g CIDR: 2.6 � 0.2 ng mL-1; 1.38-g CIDR: 2.1 � 0.1 ng mL-1). However, progesterone concentrations from insertion until Day 21 were higher (P &amp;lt; 0.03) in cows with a 1.9-g CIDR (2.1 � 0.1 ng mL-1) than in those with a DIB (1.6 � 0.1 ng mL-1) or a 1.38-g CIDR (1.6 � 0.1 ng mL-1), with Cue-Mate (1.7 � 0.1 ng mL-1) intermediate and not different. Based on progesterone release patterns, it was concluded that Cue-Mate intravaginal devices can be used in protocols for synchronization of estrus and ovulation as with other progesterone-releasing devices.

Effects of a preovulatory administered depot gonadotrophin-releasing hormone agonist on reproductive hormone levels and pregnancy outcome in gilts

The present study aimed to explore the influence of a preovulatory administered depot gonadotrophin-releasing hormone (GnRH) agonist (GnRHa; Decapeptyl Depot) on the endocrine parameters and pregnancy outcome of gilts (n = 6). A GnRHa-supported preovulatory luteinising hormone (LH) surge was detected in all treated gilts. LH pulses were abolished completely by depot GnRHa on Day 7 and partly on Day 21 of pregnancy. In this treatment group (n = 6) four gilts were pregnant at slaughter on Day 28. In the control group receiving Gonavet, a non-formulated GnRHa (n = 6), all pigs showed LH pulses and were pregnant at slaughter on Day 28 of gestation. Mean progesterone concentrations were elevated in controls during the early luteal phase and were similar for both groups during the implantation period. Mean concentration of unoccupied progesterone receptor was significantly higher in uterine myometrium than in endometrium, but without treatment effects. Peripheral estrone sulfate concentrations showed a similar increase in all pregnant gilts on Days 17 and 18, and remained elevated. In summary, treatment with a depot GnRHa for synchronisation of ovulation alters pulsatile LH secretion during early pregnancy in pigs. In general, this alteration seems not to exert an injurious influence on luteal function and, therefore, on embryo and early fetal development.

Controlling interrelationships of progesterone/LH and estradiol/LH in mares

The interrelationships of progesterone, estradiol, and LH were studied in mares ( n = 9), beginning at the first ovulation (Day 0) of an interovulatory interval. An increase in mean progesterone concentrations began on Day 0 and reached maximum on Day 6, with luteolysis beginning on Day 14. A common progesterone threshold concentration of about 2 ng/ml for a negative effect on LH occurred at the beginning and end of the luteal phase. Progesterone and LH concentrations decreased at a similar rate from Day 6 until the onset of luteolysis on Day 14, consistent with a decreasing positive effect of LH on progesterone. Concentrations of LH during the increase in the ovulatory surge consisted of two linear regression segments involving a rate of 0.4 ng/ml/day for Days 14–22 and 1.8 ng/ml/day for Day 22 to 1 day after the second ovulation. The end of the first segment and beginning of the second segment was 2 days before ovulation and was the day the ovulatory estradiol surge was at a peak.

Influence of estradiol on adrenal activity in ovariectomized cows during acute stress

Stress-dependent activation of the hypothalamo-pituitary-adrenal axis (HPA) can compromise reproductive function in animals and humans. In addition, it has been shown that estrogens are also capable of influencing the activity of the adrenal cortex. The objective of this study was to evaluate the effect of estradiol (E2) on adrenocortical secretion of cortisol and progesterone as well as on pituitary LH-release in cows during stress. Five ovariectomized Brown Swiss cows were exposed to acute restraint stress (2-h immobilization in a trimming chute), either with or without E2 treatment. Blood samples were taken every 15 min during a 5-h period for determination of cortisol progesterone and LH. Our results demonstrate that during the 2-h stress period mean cortisol concentrations significantly ( P < 0.05) increased in all cows independent of E2 treatment. Mean progesterone concentrations also increased during stress, but the effect was only significant in E2-untreated cows. In contrast to cortisol and progesterone, mean LH values decreased in all animals during stress, but the decline was not significant. However, significantly lower mean LH values were seen at the end of the stress period comparing to values before stress. In cows without stress, E2 treatment had no significant effect on mean values of all three hormones analyzed. From our results it can be concluded that in ovariectomized cows (a) acute stress increases cortisol and progesterone secretion but decreases LH release and (b) the stress induced adrenocortical and pituitary responses were clearly attenuated under the influence of estradiol.

Seasonal effects on attempts to synchronize estrus and ovulation by intravaginal application of progesterone-releasing device (PRID™) in mares

To investigate seasonal effects on the efficacy of estrus synchronization in mares, we administered a progesterone-releasing device (PRID™) intravaginally to eight Haflinger mares for 11 days. In January 3 of 8 mares responded to the treatment with estrus and ovulation, in March 7 with estrus and 6 of 7 mares with ovulation, in June 6 of 7 and in October 7 of 8 mares with estrus and ovulation. Follicle distribution patterns at PRID™ insertion were different between January/October, March/June and June/October ( P < 0.05). Number of follicles decreased during PRID™ treatment in January, March and June (difference of number of follicles at Day 12 minus number of follicles at Day 1: −4.2 ± 2.7, −0.9 ± 0.9 and −4.9 ± 1.5 follicles), while it increased in October (3.9 ± 1.2 follicles; P < 0.05). Mean progesterone concentrations were lowest in January (0.3 ± 0.1 ng mL −1) when compared with March (3.5 ± 1.8 ng mL −1; P = 0.063), June (4.4 ± 1.4 ng mL −1; P < 0.05) and October (2.2 ± 0.9 ng mL −1; P < 0.05). At Day 2 of PRID™ treatment, mean progesterone concentrations significantly increased in all mares. Except from January, mean LH concentrations decreased within one day after PRID™ insertion and remained at low levels during treatments in January and March. Total secretion of LH during PRID™-treatment was significantly lower in January and March when compared with June and October. In the 5 of 7 mares that ovulated during PRID™ treatment a distinct increase of plasma LH concentrations after ovulation was detected. Administration of the progesterone releasing intravaginal device PRID™ combined with the PGF2α analogue cloprostenol was able to induce estrus and ovulation in mares at different times of the year. However, efficacy of the treatment was not satisfactory concerning effectiveness in relation to season and synchrony of intervals from removal of PRID™ to ovulation in mares.

Effects of early prenatal exposure to 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) on postnatal reproduction in the laying hen ( Gallus gallus)

This study demonstrates the long-term effects of very early embryonic exposure to a single dose of 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) (0, 10 and 20 ng/egg), administered before the beginning of embryonic development, on growth and reproductive performance in laying hens. Hatchability and body weight gain from 11 weeks onwards were significantly depressed in 20 ng treated hens. All hens started laying egg at around the same age and the laying performance of TCDD-treated hens was normal. No disturbances in the age-related pattern and concentrations of oestradiol, LH or FSH in plasma could be found but mean progesterone concentrations were significantly lower in 20 ng treated hens. Moreover, follicular distribution was changed with less small white follicles and smaller yellow follicles, which probably resulted in the lower egg weight of the 20 ng treated hens. At 43 weeks of age, hens treated in ovo with TCDD showed a retained right oviduct, mostly filled with clear fluid. From these results, it seems that in ovo exposure to TCDD interferes in the right oviduct regression during embryonic development and induces some changes in follicular distribution but without impairment of reproductive performance in the adult laying hen.

Seasonal variations in reproductive hormones in free-ranging echidnas ( Tachyglossus aculeatus): Interaction between reproduction and hibernation

We measured the reproductive steroids testosterone and progesterone in free-ranging adult echidnas over several years. For months other than June–August, the mean progesterone concentration was 0.18 ± 0.12 ng ml −1 ( n = 14), and all blood samples taken from active female echidnas in June–August had progesterone concentrations above 0.5 ng ml −1. The highest progesterone value measured was 13.4 ng ml −1 in a pregnant female several days before egg-laying. For months other than June–August the mean testosterone concentration was 0.09 ± 0.05 ng ml −1 ( n = 13). During June–August all active sexually mature males had testosterone concentrations in excess of 0.2 ng ml −1 and were found in mating groups at some time during this period. The highest plasma testosterone concentration measured was 4.62 ng ml −1.

Manipulation of estrous cycle in Dwarf goat ( Capra hircus) using estrumate under different management conditions

A study was conducted to elucidate the effectiveness of exogenous estrumate (prostaglandin F 2α) treatment as a synchronizing agent for Dwarf goats and to establish the progesterone levels at different reproductive stages under two different environmental and nutritional conditions. Female Dwarf goats of various ages were raised, 10 each at two sites, viz. the Bio-Saline Research Substation (BSRS), Lahore and at the Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad. The animals at the NIAB farm were reared on non-saline soil under normal grazing conditions, while the other animal lot was raised on salt-affected lands at the BSRS, Lahore and was fed on non-conventional fodders produced by salt-affected lands. The animals received two intramuscular doses (0.5 ml each) of estrumate (125 μg/ml) at 10 days interval. Nineteen of the 20 animals exhibited estrus after 56–72 h of the second injection of estrumate. The mean progesterone concentration in the NIAB and BSRS lots was 2.8 and 2.4 ng/ml, respectively, at the time of second injection and declined to the basal level (estrus) within 48 h. A gradual increase in the progesterone level occurred during the metestrus, reaching maximum during the luteal phase when it was 6.3 and 6.7 ng/ml in NIAB-lot and BSRS-lot, respectively. During the proestrous phase, the progesterone level decreased to the basal level (0.1 ng/ml) at the onset of the next estrus after 22 days. The length of the induced or natural estrous cycle (20 ± 1 days) was not affected by the estrumate treatment, nor by the environmental and nutritional conditions. Breeding was allowed after the natural estrous cycle at the onset of third estrus and a high fertility rate (95%) was achieved. The progesterone concentrations remained at higher level (4.5–9.4 ng/ml) throughout the gestation period, declined gradually in the prepartum period, and dropped to the basal level at the completion of parturition. The results suggested that estrumate is an efficient synchronizing agent for the Dwarf goats kept under different environmental-nutritive conditions and that the progesterone profile is a useful indicator to assess the reproductive status of the goats.

Alteration of Reproductive Hormone Levels in Pregnant Sows Induced by Repeated ACTH Application and Its Possible Influence on Pre- and Post-natal Hormone Secretion of Piglets

Prenatal stress has been seen as a reason for reproductive failures in pig offspring mostly originated or mediated by changed maternal functions. Experiments were conducted in pregnant gilts (n=32) to characterize effects of elevated maternal glucocorticoids on the secretion of reproductive hormones (LH, progesterone) during the 1st (EXP 1), 2nd (EXP 2) and 3rd (EXP 3) trimester of pregnancy (TP). Transiently elevated cortisol release was repeatedly achieved by application of 100 IU adenocorticotropic hormone (ACTH) (Synacthen Depot) six times every second day beginning either on day 28 (EXP 1), day 49 (EXP 2) or day 75 of pregnancy (EXP 3). Glucocorticoid concentrations were examined in umbilical blood vessels of fetuses which mothers were subjected to ACTH at 2nd and 3rd TP (EXP 4). Furthermore, the pituitary function of newborn piglets of EXP 2 was checked by a LH-RH challenge test. In sows, LH concentrations were at low basal level (0.1-0.2 ng/ml) but with pulsatory release pattern during each TP. The number of LH pulses/6 h (LSM +/- SE) of saline treated Controls increased with ongoing pregnancy and decreased to the 3rd TP (1.3 +/- 0.2 in EXP 1 vs. 2.0 +/- 0.1 in EXP 2 vs. 1.4 +/- 0.1 in EXP 3, p<0.05). After ACTH treatment the number of LH pulses left unchanged in Experiments 1 and 2 (1.3 +/- 0.2 and 1.5 +/- 0.1) and decreased in EXP 3 (0.8 +/- 0.2, p<0.05). Differences (p<0.05) were obtained comparing the LH pulse number of ACTH and saline treated sows at the 2nd and 3rd TP. Moreover, areas under the curve (AUC) of each LH pulse and of LH over baseline were significantly reduced by treatment. Levels of progesterone increased (p<0.05) for 150 to 170 min after each ACTH application both in EXP 1 and EXP 2, but not in EXP 3. The mean progesterone concentration was different between trimesters, and ACTH and Controls (1st TP: 30.0 +/- 0.9 and 24.4 +/- 0.7 ng/ml; 2nd TP: 35.5 +/- 0.9 and 29.1 +/- 1.0 ng/ml; 3rd TP: 13.6 +/- 0.2 and 13.1 +/- 0.1 ng/ml; p<0.05). In fetuses (n=87) recovered 3 h after ACTH or saline (EXP 4), the plasma cortisol concentrations were significantly increased in umbilical vein (93.7 +/- 5.5 vs. 47.0 +/- 5.3 nmol/l) and artery (95.7 +/- 5.4 vs. 66.4 +/- 5.4 nmol/l), and in periphery (46.8 +/- 5.3 vs. 27.1 +/- 5.3 nmol/l) compared to controls. Plasma ACTH concentrations, however, did not differ in fetuses of both treatment groups. Postnatal LH-RH challenge tests (1st and 28th day post partum) induced LH surges in female piglets (n=67) both of ACTH and saline treated sows, but did not differ between groups (1st day: 7.2 +/- 0.8 vs. 8.1 +/- 0.7 ng/ml; 28th day: 10.5 +/- 1.7 vs. 13.6 +/- 2.2 ng/ml). However, basal LH of piglets whose mothers were submitted to ACTH during 2nd TP was lower on 1st day (1.7 +/- 0.2 vs. 2.3 +/- 0.2 ng/ml, p<0.05) but not on 28th day (1.0 +/- 0.2 vs. 1.1 +/- 0.2 ng/ml). However in both groups, the basal LH was always higher on 1st as on 28th day (p<0.05). Thus, chronic intermittent ACTH administration is able to influence the release pattern of maternal reproductive hormones. However, these findings demonstrate that these effects are dependent on the stage of pregnancy. Furthermore, it was shown that maternal cortisol can cross the placenta during gestation and thus may affect maternal-fetal interactions and, as a result, reproductive function of offspring.

Follicular dynamics and steroid profiles in cows during and after treatment with progestin-based protocols for synchronization of estrus.

Two progestin-based protocols for the synchronization of estrus in beef cows were compared. Cyclic, nonlactating, crossbred, beef cows were assigned by age and body condition score to one of two treatments. Cows assigned to the MGA Select protocol were fed melengestrol acetate (MGA; 0.5 mg x cow(-1) x (-1)) for 14 d, GnRH was administered (100 microg i.m. of Cystorelin) 12 d after MGA withdrawal, and PGF2alpha (25 mg of i.m. Lutalyse) was administered 7 d after GnRH. Cows assigned to the 7-11 Synch protocol were fed MGA for 7 d and were injected with PG on d 7 of MGA, GnRH on d 11, and PG on d 18. Transrectal ultrasonography was performed daily to monitor follicular dynamics from the beginning of MGA feeding through ovulation after the synchronized estrus. All cows exhibited estrus in response to PG. Mean interval to estrus was shorter (P < 0.01) for 7-11 Synch-treated cows (56 +/- 1.5 h) than for cows assigned to the MGA Select protocol (73 +/- 4.7 h). Mean interval from estrus to ovulation did not differ between treatments (P > 0.10). Variances for interval to estrus differed (P < 0.01) between treatments. Mean follicular diameter at GnRH injection, PG injection, and estrus did not differ (P > 0.10) between treatments. Relative to MGA Select, serum estradiol-17beta concentrations were higher (P < 0.01) for 7-11 Synch 2 d and 1 d before, on the day of GnRH injection, in addition to 4 d after GnRH, and 24 h after PG. Mean progesterone concentrations were greater (P < 0.01) for MGA Select cows from 4 d before to 7 d after GnRH. Forty-four percent of the variation in interval to estrus between treatments was explained by differences in estradiol-17beta concentrations 24 h after PG. This study suggests that follicular competence is likely related to steroidogenic capacity of the follicle and the endocrine environment under which growth and subsequent ovulation of the dominant follicle occurs.

Follicular dynamics and steroid profiles in cows during and after treatment with progestin-based protocols for synchronization of estrus12

Two progestin-based protocols for the synchronization of estrus in beef cows were compared. Cyclic, nonlactating, crossbred, beef cows were assigned by age and body condition score to one of two treatments. Cows assigned to the MGA Select protocol were fed melengestrol acetate (MGA; 0.5mg•cow−1•−1) for 14 d, GnRH was administered (100 μg i.m. of Cystorelin) 12 d after MGA withdrawal, and PGF2α (25 mg of i.m. Lutalyse) was administered 7 d after GnRH. Cows assigned to the 7-11 Synch protocol were fed MGA for 7 d and were injected with PG on d 7 of MGA, GnRH on d 11, and PG on d 18. Transrectal ultrasonography was performed daily to monitor follicular dynamics from the beginning of MGA feeding through ovulation after the synchronized estrus. All cows exhibited estrus in response to PG. Mean interval to estrus was shorter (P < 0.01) for 7-11 Synch-treated cows (56 ± 1.5 h) than for cows assigned to the MGA Select protocol (73 ± 4.7 h). Mean interval from estrus to ovulation did not differ between treatments (P > 0.10). Variances for interval to estrus differed (P < 0.01) between treatments. Mean follicular diameter at GnRH injection, PG injection, and estrus did not differ (P > 0.10) between treatments. Relative to MGA Select, serum estradiol-17β concentrations were higher (P < 0.01) for 7-11 Synch 2 d and 1 d before, on the day of GnRH injection, in addition to 4 d after GnRH, and 24 h after PG. Mean progesterone concentrations were greater (P < 0.01) for MGA Select cows from 4 d before to 7 d after GnRH. Forty-four percent of the variation in interval to estrus between treatments was explained by differences in estradiol-17β concentrations 24 h after PG. This study suggests that follicular competence is likely related to steroidogenic capacity of the follicle and the endocrine environment under which growth and subsequent ovulation of the dominant follicle occurs.

Dr. Ströhle and Colleagues Reply

Back to table of contents Previous article Next article Letter to the EditorFull AccessDr. Ströhle and Colleagues ReplyANDREAS STRÖHLE, M.D., ELENA ROMEO, M.D., FLAVIA di MICHELE, M.D., AUGUSTO PASINI, M.D., ALEXANDER YASSOURIDIS, Ph.D., FLORIAN HOLSBOER, M.D., Ph.D., and RAINER RUPPRECHT, M.D., ANDREAS STRÖHLESearch for more papers by this author, M.D., ELENA ROMEOSearch for more papers by this author, M.D., FLAVIA di MICHELESearch for more papers by this author, M.D., AUGUSTO PASINISearch for more papers by this author, M.D., ALEXANDER YASSOURIDISSearch for more papers by this author, Ph.D., FLORIAN HOLSBOERSearch for more papers by this author, M.D., Ph.D., and RAINER RUPPRECHTSearch for more papers by this author, M.D., Munich, GermanyPublished Online:1 Mar 2003https://doi.org/10.1176/appi.ajp.160.3.594AboutSectionsView EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail To the Editor: We thank Dr. Pearson Murphy for her comments on our recent article on neuroactive steroids in patients with panic disorder before and during paroxetine treatment. Because our article was published as a Brief Report, we had to be as brief as possible with regard to the description of our methods. Two of the seven women in both groups were postmenopausal. We agree that the reported progesterone levels of about 20 nmol/liter are too high for this study group, and we therefore have reanalyzed our gas chromatography/mass spectrometry data. In doing so, we found that when switching from steroid analysis by gas chromatography/mass spectrometry from the electron impact mode that was employed in our previous study of depression (1998) to the negative chemical ionization mode, we made a mistake with the calculation of progesterone concentrations. In our article, we reported on calculations based on m/z 178 and m/z 197, which represent both progesterone and pregnenolone (which partially coelute), instead of m/z 197, which represents progesterone only. This explains why the progesterone values reported were too high. We now have recalculated the progesterone levels using m/z 197. The corrected mean progesterone concentrations were 2.9 nmol/liter (SD=0.2) for the comparison subjects and 3.1 nmol/liter (SD=0.2) for the patients with panic disorder before paroxetine treatment. During paroxetine treatment of the patients with panic disorder, progesterone concentrations were between 2.6 nmol/liter (SD=0.2) and 2.9 nmol/liter (SD=0.3). The other steroid concentrations reported are correct. We seriously apologize for this error and thank Dr. Pearson Murphy for bringing up this issue, which enables us to provide the correct progesterone data. The slight differences between the correct progesterone data and those reported in our previous article regarding depression (1998) are probably due to the fact that in the meantime we changed both our gas chromatography/mass spectrometry instrument and our mode of steroid analysis. FiguresReferencesCited byDetailsCited ByNone Volume 160Issue 3 March 2003Pages 594-594 Metrics History Published online 1 March 2003 Published in print 1 March 2003

Nutritionally induced body weight loss and ovarian quiescence in Shiba goats.

Four female Shiba goats were used to determine the influence of body weight loss by dietary restriction on estrous cyclicity. The dietary restriction was started on the day following ovulation. The goats were fed hay cube and straw at an amount of 30% of energy requirement based on weekly body weight measurement. The ovaries were monitored daily by transrectal ultrasonography and blood samples were collected daily by jugular venipuncture for ovarian steroids analysis. After the start of food restriction, all animals lost body weight and entered ovarian quiescence. Intervals to the onset of ovarian quiescence tended to depend on the body weight of each animal at the start of food restriction. The mean concentration of progesterone during the mid-luteal phase (from 7 to 13 days after ovulation) in the last estrous cycle before ovarian quiescence was significantly lower than that in normal estrous cycle of the control period (19.7 +/- 2.8 vs 12.3 +/- 2.2 ng/ml, P<0.05), whereas there was no significant difference in the length of the luteal phase, determined as the period when corpora lutea existed and concentrations of progesterone were equal to or greater than 1 ng/ml (15.8 +/- 1.5 vs 15.0 +/- 2.8 days, P>0.1). A rise of estradiol concentration and follicular growth in the follicular phase following a decline of progesterone level after luteal regression tended to be suppressed at the onset of ovarian quiescence. It seems that the present results are consistent with previous findings that nutritionally induced body weight loss influences the secretion of ovarian steroids and eventually induces ovarian quiescence.