Effect of hCG application at different moments of the estrous cycle on corpus luteum and uterine vascularization and serum progesterone concentration in mares

112 selected Friesian dairy cows that had calved at least once, were used. The animals were divided into two groups, A (n = 55) and Β (n=57). On the 12th day post insemination (p.i.) 12 μg buserelin (3ml Receptal - Hoechst) and 3 ml normal saline (placebo) were injected intramuscularly to the animals of groups A and Β (controls), respectively. Milk progesterone concentration was measured in even animal from the day of insemination until the 24th day p.i.. A significant increase (P<0.05) in pregnancy rate (19.7%) was observed in the animals of group A. Also, the concentration of progesterone in the pregnant animals (14th - 24th day p.i.) as well as in the non pregnant (14th - 16th day p.i.) ones in group A was significantly increased (P<0.05) compared to that of the controls'. The duration of the estrous cycle of the non pregnant animals did not differ significantly (P>0.05) between the two groups. It is concluded that buserelin administration on the 12th day p.i. improved the fertility of dairy cows significantly by means of an antiluteolytic effect, through an increase in progesterone concentration, during the crucial period of maternal recognition of pregnancy.

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315 CORPORA LUTEA MORPHOLOGICAL AND ECHOTEXTURAL ATTRIBUTES RELATED TO PLASMA PROGESTERONE CONCENTRATION IN HEIFERS

Reproduction Fertility and Development ◽

10.1071/rdv20n1ab315 ◽

2008 ◽

Vol 20 (1) ◽

pp. 237

Author(s):

L. G. B. Siqueira ◽

J. H. M. Viana ◽

C. A. A. Torres ◽

E. D. Souza ◽

L. S. Amorim ◽

...

Keyword(s):

Corpus Luteum ◽

Estrous Cycle ◽

Ultrasound Image ◽

Computer Assisted ◽

Corpora Lutea ◽

Progesterone Concentration ◽

Plasma Progesterone ◽

Functional Changes ◽

Tissue Area ◽

Luteal Tissue

It has been suggested that ultrasound image attributes are a potential indicator of the physiological and functional status of the corpus luteum (CL). The aim of this study was to evaluate corpus luteum morphological and echotextural changes, and to correlate these changes with plasma progesterone concentration [P4] throughout the bovine estrous cycle. Crossbred heifers were scanned daily, using a B-mode, real-time ultrasound machine equipped with a 5-MHz linear-array rectal transducer, throughout a natural estrous cycle (Experiment 1; n = 12) or during a shorter estrous cycle, interrupted on the 10th day, by luteolysis induction (Experiment 2; n = 6). Blood samples were collected for further plasma [P4] analyses by RIA. Corpora lutea areas (cm2) were measured, and daily images of each CL were videotaped (VHS tapes) until digitized. Computer-assisted analyses of image attributes were performed using a custom-developed software. Daily values of luteal area, echotexture, and plasma [P4] values were analyzed by ANOVA with Tukey's test to determine differences among means of each cycle day. Pearson's correlation coefficients were calculated between luteal area, mean pixel value, pixel heterogeneity, and plasma [P4]. In the first experiment, luteal tissue area increased to a maximum on the 10th day (P < 0.05), followed by a plateau, and then declined from Day 14 to next estrus. There was a significant correlation between luteal tissue area and plasma P4 (r = 0.69; P < 0.01). In the second experiment, plasma P4 dropped to basal values 24 h after luteolysis induction. Luteal tissue area decreased at a slow rate, and reached values similar to ones from metestrus 36 h after treatment. In Experiment 1, echotexture parameters of the CL were analyzed after data adjustment to the onset of luteolysis. In both experiments, mean pixel values did not change throughout the estrous cycle and there was no correlation between mean pixel values and plasma [P4] (P > 0.10). Pixel heterogeneity changed throughout the natural estrous cycle, with maximum value on metestrus (Day 14; Day 0 = luteolysis) and minimum on diestrus (Day 2; P < 0.01). However, this parameter did not change when luteolysis was induced (Experiment 2; P > 0.10). There were significant correlations between pixel heterogeneity and plasma progesterone in both of the experiments (r = –0.69 and r = –0.48; P < 0.05). In conclusion, mean pixel values do not reflect morphological or functional changes of the CL throughout the estrous cycle. On the other hand, based on the correlations between pixel heterogeneity and systemic [P4] in both experiments, this image attribute (heterogeneity) has the potential to indicate functionality and steroidogenic capacity of the luteal gland.

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Molecular regulation of progesterone synthesis in the bovine corpus luteum

Veterinární Medicína ◽

10.17221/1996-vetmed ◽

2008 ◽

Vol 52 (No. 9) ◽

pp. 405-412 ◽

Cited By ~ 9

Author(s):

R. Rekawiecki ◽

J. Kotwica

Keyword(s):

Luteinizing Hormone ◽

Corpus Luteum ◽

Estrous Cycle ◽

Progesterone Concentration ◽

Luteal Cells ◽

Cytochrome P450scc ◽

Progesterone Synthesis ◽

Two Populations ◽

Progesterone Antagonist

In bovine luteal cells, progesterone can directly affect its own synthesis by increasing the activity of 3β-HSD. The effect of progesterone on its own secretion coincides with increased expression of the genes for 3β-HSD, StAR, and cytochrome P450scc. Therefore, progesterone regulates its own synthesis by affecting the activity of the enzymes that take part in luteal steroidogenesis, and also by affecting the expression of the genes for these enzymes. The aims of this study were: (a) to determine whether progesterone affects the expression of the gene for its own receptor, thereby affecting its own synthesis; and (b) to determine whether oxytocin and noradrenaline affect the expression of the genes for the oxytocin receptor (OT-R), the progesterone receptor (P4-R), and the β2 receptor (β2-R), thereby regulating luteal steroidogenesis. Two populations of luteal cells were used in the present study: from 6th–10th and 11th–16th days of the estrous cycle, which were isolated from corpus luteum (CL) from slaughtered cows. The luteal cells were treated for six hours with one of the following hormones: luteinizing hormone (LH; 100 ng/ml); progesterone (P4; 10–5M); progesterone antagonist (aP4; 10–5M); noradrenaline (NA; 10–5M); or actinomycin D (ActD; 500 ng/ml). After treatment, the medium was collected for the determination of progesterone concentration. With LH, the P4 concentration in the medium increased with both 6th–10th and 11th–16th days. None of the other treatments affected the progesterone concentration of the medium. The level of expression of the genes for OT-R, P4-R and β2-R were determined. Total RNA was extracted from cells, treated with DNase, and subjected to reverse transcription. Treatment with luteinizing hormone was the only treatment that increased the level of expression of the gene for P4-R in both 6th–10th and 11th–16th days of the estrous cycle. Both treatment with luteinizing hormone and treatment with progesterone increased the level of expression of the gene for OT-R in 6th–10th days. The basal level of expression of the gene for OT-R was higher in 6th–10th days than in 11th–16th days. This suggests that there is positive feedback between progesterone and oxytocin, with both playing a role as a local, intra-ovarian factor that enhances the function of the corpus luteum.

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Induction of accessory corpus luteum in cows by gonadotropin-releasing hormone administrated after insemination

Acta Veterinaria Brno ◽

10.2754/avb201483020107 ◽

2014 ◽

Vol 83 (2) ◽

pp. 107-111 ◽

Cited By ~ 2

Author(s):

Darja Musilová ◽

Jan Bartoněk ◽

Svatopluk Čech ◽

Tomáš Páleník ◽

Radovan Doležel

Keyword(s):

Dairy Cows ◽

Corpus Luteum ◽

Ultrasound Examination ◽

Gonadotropin Releasing Hormone ◽

Conception Rate ◽

Corpora Lutea ◽

Progesterone Concentration ◽

Control Groups ◽

Serum Progesterone ◽

Releasing Hormone

Sufficiency of progesterone limits conception rate in dairy cows. This study evaluates the effect of gonadotropin-releasing hormone on induction of accessory corpus luteum, progesterone concentrations and pregnancy in dairy cows. The hormone (0.05 mg) was administrated intramuscularly to cows with one corpus luteum on day 5–7 (Group E1, n = 57) or 11–13 (Group E2, n = 40) after insemination; control groups C1 (n = 54) and C2 (n = 41) were not treated. Detection of pregnancy by ultrasound examination and measurement of serum progesterone concentration was performed on day 25–39 and around day 90 after insemination. The occurrences of two corpora lutea in groups E1 and E2 versus C1 and C2 were 43.9% and 33.5% vs. 3.7% and 9.8% (P < 0.001). Progesterone concentrations were 5.9 ± 2.92 ng/ml and 7.8 ± 2.35 ng/ml in untreated and treated cows (P = 0.016), respectively. Conception rates in groups E1 and E2 were 100% and 86.7% in cows bearing two corpora lutea, and only 16.7% and 38.9% in cows bearing one corpus luteum (P < 0.01); similarly as in groups E1 and E2 compared to groups C1 and C2 (49.1% and 50% vs. 50% and 31.7%). Pregnancy rates around day 90 in groups E1 and E2 compared to groups C1 and C2 were 45.6% and 45% vs. 42.6% and 26.8%, respectively. Administration of gonadotropin-releasing hormone on day 5–7 or 11–13 after insemination was efficient to induce accessory corpus luteum and increase the concentration of serum progesterone but had no effect on the conception rate.

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PROGESTERONE IN THE HUMAN PERIPHERAL BLOOD IN THE PREOVULATORY PERIOD OF THE MENSTRUAL CYCLE

Acta Endocrinologica ◽

10.1530/acta.0.0550091 ◽

1967 ◽

Vol 55 (1) ◽

pp. 91-96 ◽

Cited By ~ 9

Author(s):

Benno Runnebaum ◽

Josef Zander

Keyword(s):

Menstrual Cycle ◽

Corpus Luteum ◽

Peripheral Blood ◽

Human Peripheral Blood ◽

Progesterone Concentration ◽

Plasma Progesterone ◽

Progesterone Secretion ◽

Graafian Follicle ◽

The Mean ◽

Mean Concentration

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.

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Serum Endocrine Profile in Relation to Estrus Synchronization in Surti Does

THE INDIAN JOURNAL OF VETERINARY SCIENCES AND BIOTECHNOLOGY ◽

10.21887/ijvsbt.v13i03.10609 ◽

2018 ◽

Vol 13 (03) ◽

Author(s):

M. M. Chaudhary ◽

C. T. Khasatiya ◽

S. B. Patel ◽

S. S. Chaudhary ◽

V. B. Atara ◽

...

Keyword(s):

Jugular Vein ◽

Estrus Synchronization ◽

Progesterone Concentration ◽

Serum Progesterone ◽

Blood Samples ◽

Group Iii ◽

Group I ◽

Endocrine Profile ◽

Group Ii ◽

And Control

The serum progesterone and estradiol profiles during synchronization of estrus by buck effect and PGF2α treatments were monitored in Surti does. Total eighteen non-pregnant does selected were evenly divided into 3 groups, 6 does in each group. The does of Group I were teased with a sexuallyactive- apronized buck; and those of Group II were treated with PGF2α, i.e., Inj. Lutalyse® @ 7.5 mg/doe IM twice 11 days apart, while the Group III served as untreated control. Blood samples were collected from all the animals on day 0 (before 1st PGF2α injection), 3rd day (during treatment), 11th day (before 2nd PGF2α injection), 14th day (after treatment) and 40th day (post-service) by jugular vein puncture. The serum separated was stored at -20°C till further analysis. In all the three groups, 83.33% does, conceived at first service in the sampling cycle. The overall mean serum progesterone concentration of Group I does (5.82±0.72 ng/ml) was significantly higher (p less than 0.01) as compared to Group II (2.93±0.38 ng/ml) and III (2.88±0.30 ng/ml). Similarly, the overall mean serum progesterone concentration of Surti does on day 0 (2.65±0.46 ng/ml), 3rd (2.56±0.80 ng/ml), 11th (4.45±0.84 ng/ml) and 14th (3.40±0.63 ng/ml) did not differ significantly, but the overall mean level at day 40 (6.31±0.45 ng/ml) was significantly (p less than 0.01) higher, because most of animals became pregnant at that time. The overall mean serum oestradiol-17β levels of Group I (24.40±2.98 pg/ ml) was significantly higher (p less than 0.01) than in Group II (15.77±1.77 pg/ml) and III (12.21±1.45 pg/ ml). On the other hand, the overall mean serum oestradiol-17β levels of Surti does on day 0 (12.89±1.21 pg/ml), 3rd (15.84±1.74 pg/ml), 11th (14.81±1.96 pg/ml), 14th (22.15±2.97 pg/ml) and 40th (21.64±5.16 pg/ml) did not differ significantly (p>0.05) and the slightly higher overall mean level found at 40th day might be the influence of the non-pregnant does at first service in the cumulative animals. The hormonal profile reflected the initiation of cyclicity and establishment of pregnancy in treated and control animals.

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