scholarly journals Diestrous Ovulations in Pregnant Mares as a Response to Low Early Postovulatory Progestogen Concentration

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2249
Author(s):  
Carolina T. C. Okada ◽  
Martim Kaps ◽  
Javier Perez Quesada ◽  
Camille Gautier ◽  
Jörg Aurich ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Prostaglandin F2α ◽  
Tissue Response ◽  
P Value ◽  
Luteal Function ◽  
Luteal Tissue ◽  
Underlying Causes ◽  
Hypothalamic Pituitary Axis ◽  
Effect Of Treatment ◽  
Response Detection

Spontaneous prolongation of the luteal phase has been described in horses, but the underlying causes are still unclear. The present study investigated details of gonadotrophin and progestogen secretion in pregnant mares (n = 11) with or without experimentally reduced early postovulatory luteal function. From days 0 to 3 after ovulation, they were treated with the prostaglandin F2α (PGF2α) analogue cloprostenol or left untreated. After conceptus collection on day 34, they were assigned to the opposite treatment. Mares were affiliated to the group primary corpus luteum (n = 6) or diestrous corpus luteum (n = 5) depending on diestrous corpus luteum (CL) detection in the PGF pregnancy. For statistical comparisons, a p-value < 0.05 was significant. There was an effect of treatment (p < 0.01), but not of group on progestogen concentration. The concentration of LH was higher in PGF-treated than in untreated pregnancies (p < 0.05), but did not differ between groups. The FSH concentration did not differ between groups nor treatments. The total luteal tissue area was greater in mares with a diestrous ovulation during the PGF treatment pregnancy. Low progestogen concentration in the early postovulatory phase diminish the negative feedback on the hypothalamic-pituitary axis in early pregnancy and, thus, stimulate a luteal tissue response. Detection of secondary CL at the time of pregnancy examination in mares may reflect that early post-ovulatory progestogen concentrations were low.

Use of pertussis toxin to investigate the mechanism of action of prostaglandin F2α on the corpus luteum in sheep

1993 ◽  
Vol 10 (1) ◽  
pp. 79-85 ◽  
Author(s):  
T J McCann ◽  
A P F Flint
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Corpus Luteum ◽  
G Protein ◽  
Mechanism Of Action ◽  
Pertussis Toxin ◽  
Prostaglandin F2α ◽  
Inhibitory Effect ◽  
Luteal Tissue ◽  
Hydrolysis Of

ABSTRACT Pertussis toxin catalysed the ADP-ribosylation of a protein of Mr 40 000 in ovine luteal tissue. Ribosylation of 45% of this protein in whole cell incubations (as judged by subsequent ribosylation of cell-free preparations in the presence of [32P]NAD) attenuated the prostaglandin (PG)F2α-stimulated hydrolysis of [3H]inositol-labelled phosphatidylinositol-4,5-bisphosphate into inositol trisphosphate by 60%, but did not affect the inhibition by PGF2α of LH-stimulated accumulation of cyclic AMP. It is concluded that activation of phospholipase C by PGF2α involves a pertussis toxin-sensitive protein, probably a G protein, and that the inhibitory effect of PGF2α on LH-stimulated adenylate cyclase is unlikely to be directly mediated by such a protein.

THE EFFECT OF PROSTAGLANDIN F2α AND PROSTAGLANDIN E2 UPON LUTEAL FUNCTION AND OVULATION IN THE GUINEA-PIG

1972 ◽  
Vol 53 (3) ◽  
pp. 493-501 ◽  
Author(s):  
F. R. BLATCHLEY ◽  
B. T. DONOVAN
Keyword(s):  
Guinea Pigs ◽  
Day Treatment ◽  
Prostaglandin F2α ◽  
Prostaglandin E ◽  
Corpora Lutea ◽  
Histamine Dihydrochloride ◽  
Luteal Regression ◽  
Luteal Function ◽  
Prostaglandin F ◽  
Effect Of Treatment

SUMMARY The effect of treatment with prostaglandin F2α (PGF2α on luteal function was examined in hysterectomized guinea-pigs. Regression of corpora lutea was found to occur when 0·25 mg (or more) was injected daily for 3 days and ovulation usually ensued within 5 days after treatment. The administration of 1 mg PGF2α daily for 7 days caused marked luteolysis but ovulation did not occur. Ovulation was blocked in three of four intact female guinea-pigs given 1 mg PGF2α/day for 7 days from day 15, but took place normally in five females injected with 0·25 mg/day. Treatment of hysterectomized guinea-pigs with 0·62 mg adrenaline hydrochloride/day, 1·97 mg atropine sulphate/day or 0·52 mg histamine dihydrochloride/day did not cause luteal regression, while the injection of 0·25 mg or 1 mg prostaglandin E2 daily for 3 days was likewise ineffective.

Potential role for lipoxygenase products of arachidonic acid in prostaglandin F2α-stimulated oxytocin release from the ovine corpus luteum

1994 ◽  
Vol 142 (1) ◽  
pp. 47-52 ◽  
Author(s):  
R G Cooke ◽  
N Ahmad
Keyword(s):  
Arachidonic Acid ◽  
Corpus Luteum ◽  
Potential Role ◽  
Prostaglandin F2α ◽  
Nordihydroguaiaretic Acid ◽  
Luteal Function ◽  
Lipoxygenase Inhibition ◽  
Lipoxygenase Products ◽  
Oxytocin Release ◽  
Prostaglandin F

Abstract Intrauterine administration of nordihydroguaiaretic acid (NDGA) will maintain luteal function in sheep and also suppress the release of both oxytocin and prostaglandin F2α (PGF2α) suggesting that 5-lipoxygenase products of arachidonic acid may be involved in ovine luteolysis. During luteolysis, uterine PGF2α is considered to be the major stimulus for the secretion of luteal oxytocin, and we report the effects of 5-lipoxygenase inhibition, via intrauterine NDGA administration, on the ability of PGF2α to effect such secretion. In the NDGA-treated ewes, luteal function was maintained and oestrus delayed, the duration of the oestrous cycle (20 ±1 days; mean ± s.d.; n=9) being significantly (P<0·01) longer than in intact controls (15 ± 1 days, n=4). Jugular infusions of PGF2α did not stimulate luteal secretion of oxytocin, the effects being comparable with those in ovariectomized ewes. In intact ewes receiving intrauterine infusions of vehicle only, PGF2α produced marked increases in luteal secretion of oxytocin. Also, preinfusion or basal concentrations of oxytocin in this group of ewes (6·6 ± 1·9 pg/ml) were significantly (P<0·01) greater than in either the NDGA-treated (3·1 ± 1·1 pg/ml) or ovariectomized (3·0 ± 0·6 pg/ml) ewes. The results suggest involvement of 5-lipoxygenase products of arachidonic acid in the release of oxytocin from the ovine corpus luteum. Journal of Endocrinology (1994) 142, 47–52

176 BLOOD FLOW TO THE CORPUS LUTEUM AND PREOVULATORY FOLLICLE AFTER OVULATION INDUCTION DURING FIRST VERSUS SECOND WAVE IN WATER BUFFALO

2015 ◽  
Vol 27 (1) ◽  
pp. 179
Author(s):  
S. Caunce ◽  
D. Dadarwal ◽  
P. S. Brar ◽  
J. Singh
Keyword(s):  
Blood Flow ◽  
Corpus Luteum ◽  
Prostaglandin F2α ◽  
Preovulatory Follicle ◽  
Dominant Follicle ◽  
Flow Area ◽  
Vascular Area ◽  
Preovulatory Follicles ◽  
Luteal Tissue ◽  
Second Wave

The objective of the study was to compare the blood flow to the corpus luteum (CL) and the preovulatory follicle in dairy buffalo (Bubalus bubalis) when ovulation was induced during the first (low to increasing progesterone levels) versus the second (luteal progesterone levels) follicular wave. We hypothesised that the wall of the first-wave dominant follicle will be less vascular compared with that of the second-wave follicle. The study was conducted during the summer months in Punjab, India. Ovulation was synchronized with prostaglandin F2α (PGF) IM followed by gonadotropin-releasing hormone (GnRH) IM 48 h later (Day 0) and buffaloes were randomised to first wave (FW; n = 6) and second wave (SW; n = 7) groups. FW group was given PGF on Days 6.5 and 7, and GnRH on Day 9.5 followed by AI (14–16 h after GnRH). The SW group was given GnRH on Day 7 (to induce ovulation of first-wave dominant follicle without luteolysis and synchronous emergence of next wave), PGF on Days 13.5 and 14, GnRH on Day 16.5 followed by artificial insemination. Transrectal colour Doppler ultrasonography (MyLab5 Vetwith 7.5 MHz transducer, Esaote S.p.A, Genoa, Italy) was performed daily and 20-s cineloops of each ovary were recorded under standardized gain controls. Images from the cineloops were processed using Fiji (ImageJ, National Institutes of Health, Bethesda, MD, USA) to calculate the area of blood flow (coloured area = vascular area, grey scale area = tissue area, and their ratio) for the preovulatory follicle (on the day before ovulation) and luteal tissue (on the day of PGF injection and 4 days post-ovulation). Data were analysed by t-test from the animals that ovulated one day before (n = 3) or the day of AI (n = 6) and had a functional CL at day 5 post-AI (FW n = 5, SW n = 4). FW follicles ovulated on 8.6 ± 0.3 days from wave emergence compared with SW follicles on 10.0 ± 0.6 days (P < 0.05) but were similar in size (i.e. follicular area on the day before ovulation did not differ between groups; P = 0.5). There was no difference in the blood flow area in the wall of preovulatory follicles (P = 0.4). Vascular area of follicles was strongly correlated with their diameter (r = 0.87). Follicles >13.5 mm in diameter had more blood flow in their wall than smaller follicles (P < 0.01). FW had a tendency (P = 0.07) for smaller luteal area on the day of PGF treatment (FW = 171 ± 24 mm2; SW = 332 ± 81 mm2) and tended (P = 0.06) to have less vascular area in the CL compared to SW group (FW = 30 ± 6 mm2; SW = 67 ± 17 mm2). There was no difference (P = 0.5) between the groups for vascular to CL area ratio. The area of luteal tissue and blood flow to the CL at Day 4 post-ovulation did not differ between the groups (P = 0.4). The diameter of the preovulatory follicle (11.6–15.7 mm) was not correlated with the cross-sectional area of developing CL at Day 4 post-ovulation (r = 0.09). In conclusion, vascularity to preovulatory follicles originating from the first wave v. second wave did not differ and preovulatory follicles ≥13.5 mm were more vascular than smaller follicles. Research was funded by NSERC; the first author was funded by scholarships from WCVM and GADVASU.

THE CORPUS LUTEUM OF THE SHEEP: EFFECT OF THE CONCEPTUS ON LUTEAL FUNCTION AT SEVERAL STAGES DURING PREGNANCY

1969 ◽  
Vol 43 (2) ◽  
pp. 301-307 ◽  
Author(s):  
R. M. MOOR ◽  
L. E. A. ROWSON ◽  
MARY F. HAY ◽  
B. V. CALDWELL
Keyword(s):  
Corpus Luteum ◽  
Local Effect ◽  
Human Chorionic Gonadotrophin ◽  
Uterine Horn ◽  
Corpora Lutea ◽  
Luteal Function ◽  
Intact Uterus ◽  
Luteal Tissue ◽  
First 90 Days ◽  
The Relationship

SUMMARY The relationship between the conceptus and the corpus luteum during the first 90 days of pregnancy was determined in sheep which were made unilaterally pregnant by egg transfer 4 or 5 days after oestrus. Additional corpora lutea were established approximately 24 hr. after an injection of human chorionic gonadotrophin given on day 20, 30, 50 or 70, and 18–24 days later the sheep were killed. When 17 unilaterally pregnant ewes, in which new corpora lutea had been induced on or before day 31, were killed, only the corpora lutea on the same side as the gravid horn were still functional; total regression of the corpora lutea had occurred in the ovary adjacent to the non-gravid horn. In 13 out of 14 sheep in which corpora lutea had been induced on day 51 or 71, the luteal tissue was still present in both ovaries at autopsy. Thus a local effect is exerted during the first one-third of pregnancy by conceptuses confined to one uterine horn, but this effect changes to a more general one about day 50. In five sheep, embryos were allowed to develop in an intact uterus and under these conditions no unilateral effect could be demonstrated on corpora lutea induced on day 31.

Control of progesterone and inhibin secretion during the luteal phase in the macaque

1991 ◽  
Vol 128 (1) ◽  
pp. 107-113 ◽  
Author(s):  
K. B. Smith ◽  
H. M. Fraser
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Single Injection ◽  
Metabolic Clearance ◽  
Serum Concentrations ◽  
Inhibitory Effects ◽  
Metabolic Clearance Rate ◽  
Luteal Function ◽  
Lhrh Antagonist ◽  
Effect Of Treatment

ABSTRACT We investigated the temporal relationship between serum concentrations of progesterone and immuno-reactive inhibin after treatment with an LHRH antagonist ([N-Ac-d-Nal(2)1,d-pCl-Phe2,d-Trp3,d-hArg(Et2)6,d-Ala10]-LHRH), during the mid-luteal phase in the macaque. Further, in an attempt to obtain a model of transitory suppression of luteal function, the effect of treatment with the LHRH antagonist for 1, 2 or 3 days during the mid-luteal phase on serum concentrations of progesterone and immunoreactive inhibin was compared. Differences in the pattern of decline of the two hormones were observed. Progesterone concentrations fell by 6 h after antagonist administration while inhibin was not significantly suppressed until 48 h. Treatment with three injections of LHRH antagonist caused a sustained suppression of luteal function as shown by low serum concentrations of progesterone and inhibin. Recovery of progesterone and inhibin secretion was observed in two out of six macaques treated with two injections of antagonist and in three out of six treated with a single injection. Therefore, with the regimens of LHRH antagonist which we employed this approach was not conducive to obtaining a reliable transitory suppression of luteal function. To elucidate further the gonadotrophin control of inhibin, six macaques were treated with three injections of the LHRH antagonist to induce a permanent suppression of luteal function but received concomitantly either human chorionic gonadotrophin (hCG) or human FSH daily for 5 days (n = 3 per group). FSH failed to prevent the antagonist-induced fall in progesterone and inhibin while hCG treatment completely reversed the inhibitory effects of the LHRH antagonist. These results give further support to the concept that the secretion of inhibin, like progesterone, is integrated with the LH control of the corpus luteum. The slower decline in inhibin after LHRH antagonist suggests that the gonadotrophic stimulus to the corpus luteum results in a more prolonged stimulus for inhibin than for progesterone secretion, or that inhibin has a longer metabolic clearance rate. Journal of Endocrinology (1991) 128, 107–113

Localization of oxytocin and neurophysin in baboon (Papio anubis) corpus luteum by immunocytochemistry

1986 ◽  
Vol 113 (4) ◽  
pp. 570-575 ◽  
Author(s):  
Firyal S. Khan-Dawood
Keyword(s):  
Corpus Luteum ◽  
Rabbit Serum ◽  
Corpora Lutea ◽  
Positive Staining ◽  
Normal Rabbit Serum ◽  
Fallopian Tubes ◽  
Papio Anubis ◽  
Luteal Cells ◽  
Luteal Tissue ◽  
Immunocytochemical Reaction

Abstract. Immunoreactive oxytocin is detectable in the corpora lutea of women and cynomolgus monkeys by radioimmunoassay. To localize the presence of oxytocin and neurophysin I in ovarian tissues of subhuman primates, three corpora lutea and ovarian stromal tissues and two Fallopian tubes obtained during the menstrual cycle of the baboon and decidua from two pregnant baboons were examined using highly specific antisera against either oxytocin or neurophysin I and preoxidase-antiperoxidase light microscopy immunohistochemistry. Oxytocin-like as well as neurophysin I-like immunoreactivities were found in some cells of all the corpora lutea only, but could not be demonstrated in ovarian stromal tissues, Fallopian tubes and decidua. Specificity of the immunocytochemical reaction was further confirmed by immunoabsorption of the antiserum with excess oxytocin or neurophysin, after which the immunoreactivities for both oxytocin and neurophysin in the luteal tissue were negative. Similar controls using normal rabbit serum gave no positive staining for either oxytocin or neurophysin. Counterstaining of the positive immunoreactivities for oxytocin and neurophysin I with Mayer's haematoxylin and eosin demonstrated clearly that the oxytocin and neurophysin I appeared as granular material mainly within the cytoplasm of the luteal cells. The localization of immunoreactive oxytocin and neurophysin I in the corpus luteum of the baboon demonstrates directly the presence of these two neurohypophysial peptides within primate luteal cells and suggests their local production.

GESTOGENS IN CORPUS LUTEUM OF CATTLE

1960 ◽  
Vol XXXIII (III) ◽  
pp. 417-427 ◽  
Author(s):  
John Kristoffersen
Keyword(s):  
Corpus Luteum ◽  
Average Value ◽  
Spectrophotometric Methods ◽  
The Third ◽  
Quantitative Measurements ◽  
Before And After ◽  
Luteal Tissue ◽  
In Pregnancy

ABSTRACT By means of chromatographic and spectrophotometric methods progesterone and a substance closely similar to 20β-hydroxy-pregn-4-ene-3-one has been detected in luteal tissue from non-pregnant and pregnant cows. In 21 animals quantitative measurements based on a method giving an average net recovery of 56 per cent showed that in pregnancy the average progesterone content in the corpus luteum reached a maximum in the third to fifth month, with low values before and after this period. For 6 nonpregnant cows, the average value was 20.2 μg/g tissue, which is considerably higher than previous values reported in the literature. The relation between these findings and the bovine dependence on a functional corpus luteum in pregnancy is discussed, and it is pointed out that more information about the metabolism of progesterone in cattle is highly desirable.

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