A study of the luteolytic mechanism of the antiprogesterone RU486 during the late-luteal phase in pseudopregnant rats

1996 ◽  
Vol 150 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Y Nakamura ◽  
H Tamura ◽  
M Ono ◽  
K Shimamura ◽  
N Sugino ◽  
...  
Keyword(s):  
Subcutaneous Injection ◽  
Luteal Phase ◽  
Treated Group ◽  
Sesame Oil ◽  
Serum Prolactin ◽  
Control Group ◽  
Serum Progesterone ◽  
Blood Samples ◽  
Serial Blood ◽  
Late Luteal Phase

Abstract The purpose of this study was to examine the possible mechanism through which RU486 induces luteolysis during the late-luteal phase in pseudopregnant (PSP) rats. PSP rats received a subcutaneous injection of RU486 in sesame oil (5 mg/kg body weight) or sesame oil alone once a day between day 9 and day 11 of pseudopregnancy. Serial blood samples were collected on days 5, 9, 10, 11 and 12 and assayed for progesterone content. To examine the possible action of RU486 through a uterine and/or a pituitary (prolactin-dependent) mechanism, PSP rats and chronic hysterectomized PSP rats which had been hysterectomized before PSP induction received a subcutaneous injection of RU486 in sesame oil (5 mg/kg body weight), sesame oil alone, prolactin in 50% polyvinylpyrrolidone (15 IU/day), or RU486 and prolactin once a day between day 9 and day 11 of pseudopregnancy. Serial blood samples were collected on days 5, 9, 10 and 11 and assayed for progesterone content. Blood samples were also collected at 0400 h on day 12 and used for prolactin and progesterone determinations. To examine the direct effect of RU486 on corpus luteum and/or pituitary, hysterectomized rats underwent hypophysectomy and pituitary autotransplantation on dioestrus 1 and received a subcutaneous injection of RU486 in sesame oil or sesame oil alone for 3 days between day 21 and day 23 after surgery. Serial blood samples were collected on days 10, 21, 22, 23 and 24 and assayed for progesterone and prolactin contents. In ordinary PSP rats, serum progesterone levels were significantly (P<0·01) lower in the RU486-treated group than in the control group (9 ± 1 vs 53 ± 7 ng/ml; mean ± s.e.m.) on day 11. Serum prolactin levels at 0400 h on day 12 of pseudopregnancy were significantly (P<0·05) lower in the RU486-treated group than in the control group (16 ±4 vs 154 ±44 ng/ml; mean ± s.e.m.). The concomitant prolactin treatment reversed the luteolytic effects of RU486 on day 11 of pseudopregnancy. In hysterectomized PSP rats, RU486 also suppressed serum prolactin levels, and the concomitant prolactin treatment again reversed the luteolytic effects of RU486. In hysterectomized rats which were hypophysectomized and pituitary autotransplanted, RU486 treatment did not induce any significant changes in serum progesterone and prolactin levels. These results indicated that RU486 induced luteolysis during the late-luteal phase in PSP rats by suppressing prolactin secretion via a hypothalamic mechanism. Journal of Endocrinology (1996) 150, 93–98

Close contact with spontaneously cycling Saint Croix ewes triggers cyclic activity in seasonally anestrous Suffolk ewes

2016 ◽  
Vol 56 (11) ◽  
pp. 1816 ◽  
Author(s):  
Agustín Orihuela ◽  
Neftalí Clemente ◽  
Rodolfo Ungerfeld
Keyword(s):  
Close Contact ◽  
Treated Group ◽  
Control Group ◽  
Progesterone Concentration ◽  
Cyclic Activity ◽  
Serum Progesterone ◽  
Blood Samples ◽  
Saint Croix

In domestic goats, oestrous activity may be induced by close contact with cyclic females. As tropical breeds of sheep show light seasonality or are even unaffected by season, the purpose of this study was to examine the hypothesis that cyclic activity may be induced in anestrous Suffolk ewes by close contact with spontaneously cycling Saint Croix ewes. The experiment was conducted with 17 anestrous Suffolk ewes that were assigned to one of two groups. Although Suffolk ewes in the Control group (n = 9) remained isolated, those of the treated group (n = 8) were joined (Day 0) and maintained in close contact with 20 Saint Croix ewes for 38 days. Serum progesterone concentration was measured in all ewes in blood samples collected on Days –8, –2, 8, 13, 18, 23, 28, 33 and 38. Before Day 0, 17/20 Saint Croix ewes were cycling, but no Suffolk ewe had luteal levels of progesterone. By Day 13, more treated than Control Suffolk ewes had progesterone luteal concentrations (8/8 vs 1/9; P = 0.0004). It was concluded that spontaneously cycling Saint Croix ewes induce cyclic activity in anestrous Suffolk ewes.

scholarly journals Therapeutic effect of hydrogen injected subcutaneously on onion poisoned dogs

2017 ◽  
Vol 61 (4) ◽  
pp. 527-533
Author(s):  
Jinghua Zhao ◽  
Ming Zhang ◽  
Yue Li ◽  
Zhiheng Zhang ◽  
Mingzi Chen ◽  
...  
Keyword(s):  
Therapeutic Effect ◽  
Subcutaneous Injection ◽  
Treated Group ◽  
Control Group ◽  
Beagle Dogs ◽  
Cell Degeneration ◽  
Blood Samples ◽  
Oxidative Products ◽  
Experimental Group ◽  
Body Count

AbstractIntroduction: The purpose of this study was to investigate the therapeutic effect of hydrogen on the therapy of onion poisoned dogs.Material and Methods: A total of 16 adult beagle dogs were divided into two groups (control and hydrogen) and all were fed dehydrated onion powder at the dose of 10 g/kg for three days. The dogs of the experimental group were given subcutaneous injection of 0.2 mL/kg of hydrogen for 12 days after making the poisoned model successful. Blood samples were collected before feeding onions, one day before injecting hydrogen, and 2 h after the injection of hydrogen on days 1, 3, 5, 7, 9, and 12. Control dogs were not treated with hydrogen.Results: The levels of leukocyte production, anaemia, red blood cell degeneration which was reflected by the values of Heinz body count, haemolytic ratio, and oxidative products in hydrogen treated group were lower than in control dogs on some days. The capacity of medullary haematopoiesis that was based on reticulocyte counts, and the antioxidation in hydrogen group were higher compared with control group. However, the differences in renal function were not obvious in both groups.Conclusion: Accordingly, it was concluded that subcutaneous injection of hydrogen could alleviate the symptoms in onion poisoned dogs.

Influence of PMSG antiserum on serum progesterone and estrous cycles of PMSG-treated gilts

1992 ◽  
Vol 72 (1) ◽  
pp. 173-176 ◽  
Author(s):  
R. N. Kirkwood ◽  
P. A. Thacker
Keyword(s):  
Key Words ◽  
Luteal Phase ◽  
Ovarian Activity ◽  
Serum Estradiol ◽  
Serum Progesterone ◽  
Estrous Cycles ◽  
Blood Samples ◽  
Effect Of Treatment

Forty-seven prepubertal gilts (88.4 ± 0.9 kg) received an injection of 750 IU PMSG to stimulate ovarian activity. After 96 h, 23 gilts received an injection of an anti-PMSG serum. Blood samples were obtained at the time of PMSG injection (day 0) and at 2, 4, 6, 11, 18, 25 and 32 d. There was no effect of treatment on serum estradiol concentrations or on the occurrence of normal estrous cycles. However, luteal phase serum progesterone concentrations were higher (P < 0.01) in gilts receiving the anti-PMSG. Key words: PMSG, antiserum, gilts, ovulation

scholarly journals Mifepristone-Induced Vaginal Bleeding Is Associated with Increased Immunostaining for Cyclooxygenase-2 and Decrease in Prostaglandin Dehydrogenase in Luteal Phase Endometrium

2002 ◽  
Vol 87 (11) ◽  
pp. 5229-5234 ◽  
Author(s):  
Dharani K. Hapangama ◽  
Hilary O. D. Critchley ◽  
Teresa A. Henderson ◽  
David T. Baird
Keyword(s):  
Luteal Phase ◽  
Vaginal Bleeding ◽  
Steroid Receptors ◽  
Cyclooxygenase 2 ◽  
Control Group ◽  
Local Concentration ◽  
Serum Progesterone ◽  
Prostaglandin Dehydrogenase ◽  
Group 2 ◽  
Midluteal Phase

Abstract The mechanism of mifepristone-induced vaginal bleeding and endometrial shedding was investigated in 13 women who took 200 mg mifepristone in the midluteal phase on d 8 after the onset of the urinary LH surge (LH+8). Endometrial biopsies were collected, 6–24 h after mifepristone (group 1, n = 7) or 36–48 h after mifepristone (group 2, n = 6), and compared with those from a control group in the midluteal phase (n = 7). All women reported vaginal bleeding commencing 36–48 h after taking mifepristone. Treatment with mifepristone significantly reduced serum progesterone levels in all women, when compared with the controls (13.2 nmvs. 34.8 nm, P = 0.001). After mifepristone, a significant increase in cyclooxygenase-2 immunoreactivity was apparent at 36–48 h (P = 0.0018), whereas prostaglandin 15 dehydrogenase enzyme-positive immunostaining declined, to be virtually absent by 36–48 h in both glands and in stroma (P &lt; 0.05). There was no change in intensity or distribution of staining for steroid receptors after mifepristone. The changes in immunostaining for cyclooxygenase-2 and prostaglandin 15 dehydrogenase strongly support the hypothesis that an increase in the local concentration of prostaglandins in the endometrium is involved in the mechanism of bleeding induced by mifepristone in the luteal phase.

Progesterone as the driving regulatory force behind serum FSH concentrations and antral follicular development in cycling ewes

2011 ◽  
Vol 23 (2) ◽  
pp. 303 ◽  
Author(s):  
Tanya E. Baby ◽  
Pawel M. Bartlewski
Keyword(s):  
Luteal Phase ◽  
Follicular Development ◽  
Treated Group ◽  
Time Frame ◽  
Oestrous Cycle ◽  
Control Group ◽  
Corpora Lutea ◽  
Follicular Waves ◽  
Follicular Wave ◽  
And Control

Ovarian antral follicles in sheep grow in an orderly succession, producing typically three to four follicular waves per 17-day oestrous cycle. Each wave is preceded by a transient increase in circulating FSH concentrations. The mechanism controlling the number of recurrent FSH peaks and emerging follicular waves remains unknown. During the ewe’s oestrous cycle, the time between the first two FSH peaks and days of wave emergence is longer than the intervals separating the ensuing FSH peaks and follicular waves. The prolonged interpeak and interwave interval occurs early in the luteal phase when low levels of progesterone are secreted by developing, or not fully functional, corpora lutea (CL). The purpose of the present study was to determine the effect of varying progesterone (P4) levels on circulating concentrations of FSH and antral follicular development in sheep. Exogenous P4 (15 mg per ewe, i.m.) was administered twice daily to six cycling Rideau Arcott × Dorset ewes from Day 0 (ovulation) to Day 4 (the mean duration of the interwave interval); six animals served as controls. Follicular growth was monitored in all animals by daily transrectal ultrasonography (Days 0–9). Jugular blood samples were drawn twice a day from Day 0 to Day 4 and then daily until Day 9 to measure systemic concentrations of P4, FSH and 17β-oestradiol (E2). The first FSH peak after ovulation was detected on Days 1.5 ± 0.2 and 4.2 ± 0.2 in treated and control ewes, respectively (P < 0.05). The next FSH peak(s) occurred on Day 3.9 ± 0.3 in the treated group and on Day 6.4 ± 0.5 in the control group. Consequently, the treated group had, on average, three follicular waves emerging on Days 0, 3 and 6, whereas the control group had two waves emerging on Days 0 and 5. Mean serum E2 concentrations were greater (P < 0.05) in control compared with treated ewes on Days 1.3, 2.3, 3.3, 4.0 and 4.3 after ovulation. In summary, creation of mid-luteal phase levels of P4 in metoestrus shortened the time to the first post-ovulatory FSH peak in ewes, resulting in the emergence of one more follicular wave compared with control ewes during the same time frame. Therefore, P4 appears to be a key endocrine signal governing the control of periodic increases in serum FSH concentrations and the number of follicular waves in cycling sheep.

Effects of an LH-releasing hormone antagonist on the secretion of LH, FSH, prolactin and ovarian steroids at different stages of the luteal phase in the stumptailed macaque (Macaca arctoides)

1986 ◽  
Vol 111 (1) ◽  
pp. 83-90 ◽  
Author(s):  
H. M. Fraser ◽  
M. Abbott ◽  
N. C. Laird ◽  
A. S. McNeilly ◽  
J. J. Nestor ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
High Amplitude ◽  
High Serum ◽  
Serum Concentrations ◽  
Blood Samples ◽  
Luteal Function ◽  
Late Luteal Phase ◽  
Lhrh Antagonist ◽  
Lh Releasing Hormone

ABSTRACT The role of the pituitary gonadotrophins in controlling luteal function in the stumptailed macaque has been investigated by examining profiles of serum concentrations of LH, FSH, progesterone and oestradiol in daily blood samples from 13 monkeys during the menstrual cycle, and in blood samples taken at hourly intervals between 09.00 and 21.00 h on different days of the luteal phase in 13 cycles. The effects of acute withdrawal of gonadotrophins was investigated by administering a single injection of 300 μg LHRH antagonist/kg body weight at different stages of the luteal phase during 28 cycles. Although there were high basal values and marked fluctuations of bioactive LH during the first 4 days after the LH peak, progesterone profiles showed no corresponding short-term changes, there being a slow and steady rise in progesterone concentrations during the sampling periods. After day 5, basal LH secretion decreased, but high amplitude LH pulses were identified which were associated with episodes of progesterone secretion. Administration of the LHRH antagonist caused a suppression of bioactive LH and progesterone concentrations at all stages of the luteal phase, although some basal secretion of progesterone was maintained through the 24-h period of effective antagonist gonadotroph blockade. Luteal function recovered apparently normally in all monkeys treated in the early–mid-luteal phase. Serum concentrations of FSH and oestradiol fluctuated comparatively less during the 12-h sampling periods, and the antagonist had less suppressive effects on the concentrations of these hormones. The LHRH antagonist had no apparent effect on prolactin release. It appears that the corpus luteum is relatively unresponsive to the high serum LH concentrations during the early luteal phase, but that responsiveness increases as the corpus luteum develops. The corpus luteum is, however, susceptible to withdrawal of LH not only in the mid–late luteal phase when the relationship with LH is apparent, but also during the early luteal phase. J. Endocr. (1986) 111, 83–90

scholarly journals Blood Ghrelin, Adiponectin and Resistin Levels During Controlled Ovarian Stimulation in IVF Cycles

2016 ◽  
pp. 809-814
Author(s):  
K. DAFOPOULOS ◽  
C. I. MESSINI ◽  
G. ANIFANDIS ◽  
P. GEORGOULIAS ◽  
D. SOURLAS ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Gnrh Agonist ◽  
Ovarian Stimulation ◽  
Luteal Phase ◽  
Controlled Ovarian Stimulation ◽  
Recombinant Fsh ◽  
Serum Progesterone ◽  
Blood Samples ◽  
Stimulation Period ◽  
First Time

The aim of the present study was to investigate changes of blood ghrelin, adiponectin and resistin levels in IVF/ICSI-ET cycles. Twenty women were stimulated with recombinant FSH in a GnRH agonist short protocol for IVF/ICSI. Blood samples were taken on cycle day 2 before the commencement of injections, on cycle day 6 and on the days of HCG injection, oocyte pick up (OPU), embryo transfer (ET) as well as 7 and 12 days post-ET. Serum E2 levels increased during the stimulation, peaking on the HCG day and declined thereafter (p<0.001). Serum progesterone levels started to increase on the OPU day, peaking on the ET day (p<0.001) and decreased on days 7 and 12 post-ET. Plasma ghrelin remained unchanged during the whole cycle. Serum adiponectin levels remained stable during the stimulation period until the ET day and decreased on days 7 and 12 post-ET (p<0.001). Serum resistin levels increased until the ET day (p<0.05), remained unchanged on day 7 post-ET and decreased on day 12 post-ET (p<0.05). The present study shows for the first time that ghrelin levels did not change significantly during IVF/ICSI-ET cycles. Resistin levels increased during the stimulation period while adiponectin levels remained stable decreasing during the luteal phase.

scholarly journals 4-Hexylresorcinol Exhibits Different Characteristics to Estrogen

2020 ◽  
Vol 10 (5) ◽  
pp. 1737 ◽  
Author(s):  
Yei-Jin Kang ◽  
Ji-Hyeon Oh ◽  
Hyun Seok ◽  
You-Young Jo ◽  
Dae-Won Kim ◽  
...  
Keyword(s):  
Western Blot ◽  
Subcutaneous Injection ◽  
Estrogen Receptor Α ◽  
Ovariectomized Rats ◽  
Histological Evaluation ◽  
Serum Prolactin ◽  
Control Group ◽  
Pituitary Glands ◽  
Mcf 7

4-Hexylresorcinol (4HR) has been used as a food additive and antiseptic. The aim of this study was to evaluate whether the application of 4HR in breast cancer cells and ovariectomized rats showed estrogen-like effects. MCF-7 and SK-BR-3 cells were treated by solvent, 1–100 µM bisphenol-A (BPA), or 1–100 µM 4HR, respectively. 3-(4, 5-Dimethylthiazole-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay and Western blot for extracellular signal-regulated kinase-1/-2 (ERK1/2), phosphorylated ERK1/2 (p-ERK1/2), estrogen receptor-α (ERα), and ERβ were done. As an in vivo study, ovariectomized rats (n = 15) received solvent, 125 mg/kg of 4HR, or 10 µg of 17-β estradiol via daily subcutaneous injection for 7 days. Blood samples were obtained for evaluation of prolactin levels. Pituitary glands and uteruses were biopsied for histological evaluation and Western blot analysis. Compared with the control group, the application of 4HR decreased the proliferation of MCF-7 and SK-BR-3 cells, while the application of BPA increased (p < 0.05). The application of BPA increased the expression of ERα, ERβ, and p-ERK1/2, but 4HR did not change the expression of ERα, ERβ, or p-ERK1/2 in MCF-7 cells. In an animal model, the 4HR group showed similar levels of ERα, ERβ, and prolactin expression in the pituitary gland compared to the solvent only group, while the estradiol group showed higher levels. Serum prolactin levels were similar between the 4HR and solvent only groups. Taken together, 1–100 µM 4HR did not show BPA-like behavior in MCF-7 cells, and 125 mg/kg of 4HR daily subcutaneous injection for 7 days did not demonstrate estradiol-like effects in ovariectomized rats. Collectively, 4HR has no estrogen-like effects on both ERα-positive cells and estrogen-deficient rat models.

183 EFFECTS OF LONG-TERM NUTRITIONAL RESTRICTION ON PREOVULATORY LUTEINIZING HORMONE SURGE, LEPTIN, AND LUTEAL PHASE IN LLAMAS (LAMA GLAMA)

2013 ◽  
Vol 25 (1) ◽  
pp. 240
Author(s):  
M. C. Norambuena ◽  
M. Silva ◽  
F. Urra ◽  
C. Ulloa-Leal ◽  
C. Letelier ◽  
...  
Keyword(s):  
Luteal Phase ◽  
Transvaginal Ultrasound ◽  
Plasma Concentrations ◽  
Maximum Diameter ◽  
Control Group ◽  
Blood Samples ◽  
Dependent Variables ◽  
Nutritional Restriction ◽  
Plasma Leptin

The aim of the study was to determine the effect of long-term energy restriction on preovulatory LH surge and luteal phase in llamas. Mature nonlactating, nonpregnant, female llamas (n = 16) were assigned randomly to the following groups: (1) llamas received Ballica sp. hay ad libitum and 300 g d–1 of commercial concentrate (control group, n = 8, BCS = 3.9) or (2) llamas were fed the same feed but the amount was progressively reduced from 70% to 40% of their maintenance energy requirement (MER) for a period of 87 days, until the final BCS was 2.5 (restricted group, n = 8). After 2 months and 21 days of 40% MER diet, ovarian follicular wave emergence was synchronized by transvaginal ultrasound-guided ablation of follicles ≥5 mm in diameter using a 17-ga needle attached to a 5-MHz convex-array transducer. Ten days after follicle ablation (Day 0), llamas were given an i.m. dose of 50 µg of gonadorelin acetate to induce ovulation. Frequent blood samples were taken every 30 min for 6 h and every 15 min for 1 h for plasma LH and leptin concentration measurements, respectively, immediately after treatment. Llamas were examined daily by transrectal ultrasonography for 20 days to record serial changes in the CL diameter. In addition, blood samples were taken every 2 days from Day 0 to 16 to determine plasma concentrations of leptin and progesterone. Discrete dependent variables were compared between groups by Student t-tests and continuous dependent variables were analysed by analyses of variance with repeated-measures. There was an effect of time on plasma LH concentration (P ≤ 0.001), but not an effect of group (P = 0.1) or interaction (P = 0.6) after gonadorelin acetate treatment. Plasma leptin concentration was lower in llamas from the restricted than that of the control group after gonadorelin treatment [effect of time, group (P ≤ 0.01), and interaction (P ≤ 0.01)]. The maximum diameter of the CL and plasma progesterone concentration were lower in the restricted than in the control group, and both variables were affected by group (P ≤ 0.01, P ≤ 0.02), and day (P ≤ 0.001, P ≤ 0.001, respectively). Plasma leptin concentration was lower in the restricted than that of the control group during the entire experiment. In conclusion, long-term nutritional restriction affected negatively CL diameter, progesterone secretion, and leptin plasma concentration in llamas. The differential response of leptin to gonadorelin acetate treatment could reflect a subfertlity-nutritional induced problem related with steroidogenesis, oocyte quality, ovulation, and early embryo development processes. Research supported by Postdoctoral Fondecyt N° 3110095.

Different wavelengths of light on GnRH mRNA, LH, steroid hormones and egg lay in the ageing hens (Gallus gallus domesticus).

2016 ◽  
Vol 5 (06) ◽  
pp. 4597
Author(s):  
Janardhan Reddy Ippala* ◽  
Ashish Mishra ◽  
Mondal S. ◽  
David G. C. ◽  
Ravi Kiran G. ◽  
...  
Keyword(s):  
Steroid Hormones ◽  
Egg Production ◽  
Treated Group ◽  
Reproductive Period ◽  
Control Group ◽  
Blood Samples ◽  
Egg Formation ◽  
High Concentrations ◽  
Normal Spectrum ◽  
And Control

The aim of this study was to investigate the effects of red spectrum of light (650nm, treated n=12) and normal spectrum of light (450nm control=12) on circulating concentrations of luteinizing hormone (LH), progesterone (P4), estradiol (E2β), GnRH mRNA, pause days and egg production in birds later in the reproductive period from 92-102weeks of age. Twenty-four White Leghorn birds of same age group were divided into two groups of 12 in each as control and treated. Birds in the control group were exposed to normal spectrum of light (450nm of length) and birds in the treated group were exposed to red spectrum of light (650nm, treated n=12). Egg production and inter sequence pauses were recorded daily from both the groups. Plasma LH, E2β and P4 concentrations were estimated in blood samples collected at weekly intervals. At 97th weeks of age, blood samples from treated and control birds were obtained every 3 h for 36 h to study the surges of LH. It was found that plasma GnRH was higher (p < 0. 01) in treated birds with high concentrations of LH, its 3 h LH surges, E2β and P4 in plasma. Higher egg production, less pause days in treated birds may be the result of high GnRH associated with positively correlated responses of high concentrations of LH (with regular interval and duration of LH surges), E2β and P4 concentration required for completion of egg formation and oviposition. In conclusion, red spectrum of light enhanced GnRH mRNA (p < 0. 01), increased (p < 0. 01) steroid hormones and LH surges, for egg formation and oviposition and enabled the birds to lay more eggs even later in the productive period with the available resources under normal husbandry practices. 

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