scholarly journals Induced ovulation, mating success and embryonic development in the stripe-faced dunnart, Sminthopsis macroura

Reproduction ◽  
2001 ◽  
pp. 777-783 ◽  
Author(s):  
DE Hickford ◽  
NE Merry ◽  
MH Johnson ◽  
L Selwood
Keyword(s):  
Oocyte Maturation ◽  
Mating Success ◽  
Luteal Phase ◽  
Intermediate Phase ◽  
Corpora Lutea ◽  
Induced Ovulation ◽  
Ovarian Histology ◽  
Sminthopsis Macroura ◽  
Combined Data ◽  
Natural Cycles

Induced ovulation resulting in normal embryos is rare in marsupials. In this study natural and induced ovulations were compared in mature Sminthopsis macroura (n = 122). Comparison of maturation of preovulatory oocytes by ovarian histology and examination of oocytes removed from developing follicles in 12 ovaries of 23 animals receiving 0.058 iu equine serum gonadotrophin (eSG) g(-1) with ovaries of 12 animals undergoing natural cycles showed that oocyte maturation was significantly more irregular when it was induced (P < 0.001). Postovulatory stages were examined by estimating the number of eggs ovulated from ovarian histology, and by counting oviduct and uterine contents recovered after ovulation. S. macroura receiving 0.087 iu eSG g(-1) (n = 34), administered as one (n = 17) or two (n = 17) injections, were significantly (P < 0.05) more likely to ovulate (74%), mate (80%) and have conceptuses (66%) than were animals receiving 0.058 iu eSG g(-1) (12, 53 and 0%, respectively) (n = 17), and the values were similar to those in animals (n = 36) undergoing natural cycles (100, 81 and 56%, respectively). Induced ovulation using 0.087 iu eSG g(-1) yielded significantly (P < 0.05) more oocytes per ovary (20.8 +/- 8.5; combined data) than did ovulation in animals undergoing natural cycles (13.7 +/- 3.2) (ANOVA, t test). The responses of animals induced in different phases of the oestrous cycle with 0.087 iu eSG g(-1) were not significantly different (ANOVA) with respect to the number of corpora lutea per ovary, conceptuses per animal or days to ovulation after injection. However, the proportion of females that responded after receiving 0.058 iu eSG g(-1) in the luteal phase was significantly different from that in animals treated with the same dose in the intermediate phase (P < 0.01) and in non-cyclic females treated with 0.058 iu eSG g(-1) (P < 0.02). The main benefits of the treatment were that normal embryos resulted and that 70-78% of non-cyclic animals could be induced to ovulate.

scholarly journals Induced ovulation mimics the time-table of natural development in the stripe-faced dunnart, Sminthopsis macroura and results in the birth of fertile young

Reproduction ◽  
2010 ◽  
Vol 139 (2) ◽  
pp. 419-425 ◽  
Author(s):  
Phil Chi Khang Au ◽  
Angela Nation ◽  
Marissa Parrott ◽  
Lynne Selwood
Keyword(s):  
Captive Breeding ◽  
Induced Ovulation ◽  
Initial Injection ◽  
Time Table ◽  
Serum Gonadotropin ◽  
Sminthopsis Macroura ◽  
Reproductive Females ◽  
Genetic Pool ◽  
Effective Conservation ◽  
Natural Cycles

Induced ovulation maximizes captive breeding success, increasing productivity and facilitating the contribution of otherwise infertile animals to the genetic pool. In marsupials, induced ovulation to produce fertile young is unknown. Here we present an induction protocol efficient in inducing non-cycling and non-reproductive females to cycle, mate, ovulate, and conceive. Ovulation was induced in Sminthopsis macroura using an initial injection of 0.06 IU equine serum gonadotropin (eSG)/g (time 0), followed on day 4 by 0.04 IU eSG/g. Using this induction regime, the timing of follicular and embryonic development mimics natural cycles and results in the birth of viable, fertile young. Response to induction is not significantly affected by animal age, making this protocol an effective conservation tool. We have established a time-table of development following induction, providing a source of precisely timed research material. This is the first induced ovulation protocol in any marsupial to result in demonstrated fertile offspring and to allow the reliable collection of known-age samples during both the follicular phase and the gestation period.

STIMULATION BY HUMAN CHORIONIC GONADOTROPHIN OF OESTRADIOL PRODUCTION BY DISPERSED CELLS FROM HUMAN CORPUS LUTEUM: COMPARISON WITH PROGESTERONE PRODUCTION; UTILIZATION OF EXOGENOUS TESTOSTERONE

1981 ◽  
Vol 91 (2) ◽  
pp. 197-203 ◽  
Author(s):  
M. C. RICHARDSON ◽  
G. M. MASSON
Keyword(s):  
Luteal Phase ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Cell Suspensions ◽  
Corpora Lutea ◽  
Progesterone Production ◽  
Late Luteal Phase ◽  
Oestradiol Production ◽  
Dispersed Cells

Cell suspensions were prepared from tissue samples of human corpora lutea obtained during the mid- and late-luteal phase of the menstrual cycle. Both oestradiol and progesterone production by dispersed cells were stimulated by similar concentrations of human chorionic gonadotrophin (hCG). As the degree of stimulation of production by hCG was greater for progesterone than for oestradiol (five- to tenfold compared with two- to threefold higher than basal production), the ratio of progesterone to oestradiol produced varied according to the level of trophic stimulation. A comparison of cell suspensions prepared from mid- and late-luteal phase corpora lutea, exposed to the same concentration of hCG (10 i.u./ml) in vitro, did not reveal a shift to oestradiol production in the late-luteal phase. Provision of additional testosterone during incubation raised the level of oestradiol production by dispersed luteal cells. At an optimum concentration of testosterone (1 μmol/l), oestradiol synthesis was not raised further in the presence of hCG or N6, O2-dibutyryl cyclic AMP, suggesting a lack of induction or activation of the aromatase system by gonadotrophin in short-term cultures. Basal and stimulated levels of progesterone production were not significantly impaired in the presence of testosterone.

Protein kinase C in uterine and systemic arteries during ovarian cycle and pregnancy

1991 ◽  
Vol 260 (3) ◽  
pp. E464-E470 ◽  
Author(s):  
R. R. Magness ◽  
C. R. Rosenfeld ◽  
B. R. Carr
Keyword(s):  
Blood Flow ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Luteal Phase ◽  
Follicular Phase ◽  
Ovarian Cycle ◽  
Corpora Lutea ◽  
Kinase C ◽  
Estrogen Production ◽  
Systemic Artery

Elevated uterine blood flow is associated with increases in local estrogen-to-progesterone ratios during the follicular phase of the ovarian cycle and late pregnancy. Because protein kinase C (PKC) activation increases arterial tone, decreased PKC activity may mediate vasodilation. Therefore, we determined uterine (UA) and systemic artery (SA, omental) PKC activity (pmol.mg protein-1.min-1) during the follicular (n = 6), early luteal (n = 4), and late luteal (n = 3) phases of the sheep ovarian cycle, and at 110 +/- 3 (n = 4) and 130 +/- 1 (n = 8) (+/- SE) days of ovine gestation. The stage of the ovarian cycle was verified by the presence of follicles (high estrogen) or corpora lutea (high progesterone) on the ovary and by plasma estrogen and progesterone concentrations. UA-PKC activity (pmol.mg protein-1.min-1) during the follicular phase was 100 +/- 18 and increased progressively to 155 +/- 28 during the early luteal phase and to 219 +/- 37 (P less than 0.05) during the late luteal phase; SA-PKC activity was unchanged. A local utero-ovarian relationship was observed, i.e., UA-PKC activity was lower (P less than 0.001) in UA ipsilateral to ovaries with only follicles (105 +/- 14) when compared with UA adjacent to ovaries with corpora lutea (224 +/- 26), which was similar to SA-PKC activity (184 +/- 35). UA-PKC activity fell from 344 +/- 70 at 110 days to 109 +/- 12 at 130 days gestation (P less than 0.05); SA-PKC activity was unchanged. During the ovarian cycle and latter one-third of ovine pregnancy, increased estrogen production is associated with decreased UA-PKC activity; thus local ovarian and placental steroids may alter PKC activity, thereby regulating UA tone and blood flow.

scholarly journals Immunohistological Localization and Expression of α-Actin in the Baboon (Papio anubis) Corpus Luteum

1997 ◽  
Vol 45 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Firyal S. Khan-Dawood ◽  
Jun Yang ◽  
M. Yusoff Dawood
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Adherens Junctions ◽  
Tunica Albuginea ◽  
Corpora Lutea ◽  
Papio Anubis ◽  
Lh Surge ◽  
Luteal Cells ◽  
Steroidogenic Cells ◽  
E Cadherin

We have recently shown the presence of E-cadherin and of α- and γ-catenins in human and baboon corpora lutea. These are components of adherens junctions between cells. The cytoplasmic catenins link the cell membrane-associated cadherins to the actin-based cytoskeleton. This interaction is necessary for the functional activity of the E-cad-herins. Our aim therefore was to determine the presence of α-actin in the baboon corpus luteum, to further establish whether the necessary components for E-cadherin activity are present in this tissue. An antibody specific for the smooth muscle isoform of actin, α-actin, was used for these studies. The results using immunohistochemistry show that (a) α-actin is present in steroidogenic cells of the active corpus luteum, theca externa of the corpus luteum, cells of the vasculature, and the tunica albuginea surrounding the ovary. The intensity of immunoreactivity for α-actin varied, with the cells of the vasculature reacting more intensely than the luteal cells. A difference in intensity of immunoreactivity was also observed among the luteal cells, with the inner granulosa cells showing stronger immunoreactivity than the peripheral theca lutein cells. There was no detectable immunoreactivity in the steroidogenic cells of the atretic corpus luteum. However, in both the active and atretic corpora lutea, α-actin-positive vascular cells were dispersed within the tissue. (b) Total α-actin (luteal and non-luteal), as determined by Western blot analyses, does not change during the luteal phase and subsequent corpus luteum demise (atretic corpora lutea). (c) hCG stimulated the expression of α-actin and progesterone secretion by the early luteal phase (LH surge + 1–5 days) and midluteal phase (LH surge + 6–10 days) cells in culture, but only progesterone in the late luteal phase (LH surge + 11–15 days). The data show that α-actin is present in luteal cells and that its expression is regulated by hCG, thus suggesting that E-cadherin may form functional adherens junctions in the corpus luteum.

A comparative study of the corpus luteum

1995 ◽  
Vol 7 (3) ◽  
pp. 303 ◽  
Author(s):  
RT Gemmell
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Secretory Granules ◽  
Hormonal Control ◽  
Egg Laying ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Embryonic Diapause ◽  
Alternative Reproductive Strategy ◽  
Uterine Development

The corpus luteum (CL) is a transitory organ which has a regulatory role in reproduction. Sharks, amphibians and reptiles have corpora lutea that produce progesterone which influences the rate of embryonic development. The egg-laying monotremes and the two major mammalian groups, eutherian and marsupial, have a CL that secretes progesterone. Most eutherians have allowed for the uterine development of their young by extending the length of the oestrous cycle and the CL or placenta actively secretes progesterone until birth. Gestation in the marsupial does not extend beyond the length of an oestrous cycle and the major part of fetal development takes place in the pouch. Where the extension of the post-luteal phase in the eutherian has allowed for the uterine development of young, the marsupial has extended the pre-luteal phase of the oestrous cycle and has evolved an alternative reproductive strategy, embryonic diapause. The mechanism for the secretion of hormones from the CL has been controversial for many years. Densely-staining secretory granules have been observed in the CL of sharks, marsupials and eutherians. These granules have been reported to contain relaxin, oxytocin or mesotocin, and progesterone. A hypothesis to suit all available data is that all hormones secreted by the CL are transported within such granules. In conclusion, although there are obvious differences in the mode of reproduction in the two main mammalian groups, it is apparent that there is a great deal of similarity in the hormonal control of regression of the CL and parturition.

Seasonal reproduction in the highveld mole-rat, Cryptomys hottentotus pretoriae (Rodentia: Bathyergidae)

2002 ◽  
Vol 80 (5) ◽  
pp. 810-820 ◽  
Author(s):  
L Janse van Rensburg ◽  
N C Bennett ◽  
M van der Merwe ◽  
A S Schoeman
Keyword(s):  
Body Mass ◽  
Reproductive Tract ◽  
Plasma Testosterone ◽  
Breeding Period ◽  
Corpora Lutea ◽  
Seasonal Breeding ◽  
Nonbreeding Season ◽  
Ovarian Histology ◽  
Mole Rat ◽  
Reproductive Females

The highveld mole-rat, Cryptomys hottentotus pretoriae, is a cooperatively breeding rodent that exhibits seasonal breeding and a reproductive division of labour. Body mass, reproductive-tract morphometrics, ovarian histology, and plasma oestrogen and progesterone concentrations were studied for both reproductive and non-reproductive females from 55 colonies, the main objective being to determine the inclination of this species towards seasonal breeding. Offspring are born from July through to November. However, qualitative analysis of ovarian histology revealed that reproductive females retain the potential for ovulation and subsequent production of corpora lutea during the late-summer nonbreeding period (December–March). Seasonal differences were found in ovarian morphometrics and hormone concentrations that are associated with enhanced follicular activation in April and May and subsequent conceptions from July through to November during the breeding period. The nonbreeding period coincides with maximal dispersal opportunities in the summer-rainfall areas inhabited by the highveld mole-rat. Body mass, reproductive-tract morphometrics, testicular histology, and plasma testosterone concentrations were determined for reproductive and non-reproductive males from 37 colonies. Available evidence suggests that there is a gradual increase in testicular mass for reproductive males as the breeding season approaches, but after September the testicular parameters fall. Seminiferous-tubule diameter was significantly greater in reproductive males but exhibited no seasonal variation. Testosterone concentrations were higher in reproductive males. Current data support a lack of gonadal regression in males during the nonbreeding season.

P-681 Will the hCG trigger dose used for final oocyte maturation in IVF impact endogenous progesterone during the luteal phase? - A randomized controlled trial

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
L Svenstrup ◽  
J Fedder ◽  
S Möller ◽  
D Pedersen ◽  
K Erb ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Luteal Phase ◽  
Controlled Trial ◽  
University Hospital ◽  
Final Oocyte Maturation ◽  
Randomized Controlled ◽  
Number Of Patients ◽  
Significant Difference ◽  
Hcg Trigger ◽  
Group 1

Abstract Study question Is there an association between the hCG dose used for ovulation trigger and the endogenous progesterone production during the luteal phase? Summary answer Increased hCG dosing significantly increased the endogenous progesterone level during the luteal phase. What is known already During the luteal phase of an IVF treatment, the endogenous progesterone (P4) production is negatively impacted due to reduced circulating endogenous LH, caused by negative feed-back of elevated steroids; thus, luteal phase support (LPS) with exogenous P4 remains mandatory in IVF. Apart from inducing final oocyte maturation, the gold standard HCG trigger also functions as an early LPS, boosting P4 production by the corpora lutea (CL). P4 plays a pivotal role for embryo implantation and pregnancy, and an optimal P4 level around peri-implantation seems to be essential for the reproductive outcomes of fresh and frozen/thaw embryo transfer cycles. Study design, size, duration A randomized controlled 4-arm study, including a total of 127 IVF patients, enrolled from January 2015 until September 2019 at the Fertility Clinic, Odense University Hospital, Denmark. Participants/materials, setting, methods IVF patients with ≤ 11 follicles ≥ 12 mm were randomized to four groups. Groups 1-3 were triggered with: 5.000 IU, 6.500 IU or 10.000 IU, hCG, respectively, receiving a LPS consisting of 17-α-hydroxy-progesterone (17α OH P4) to distinguish the endogenous P4 from the exogenous supplementation. Group 4 (control) was randomized to a 6.500 IU hCG trigger and standard LPS. A total of eight blood samples were drawn during the early luteal phase. Main results and the role of chance A total of 94 patients completed the study: 21, 22, 25 and 26 patients in each group, respectively. Baseline characteristics were similar, except for the endogenous LH level and cycle lengths. There were no significant differences between groups regarding ovarian stimulation, number of oocytes and embryos. The median number of follicles ≥ 12mm on the day of trigger was 8.5, resulting in 6.6 oocytes being retrieved. Significant differences in P4 levels were seen at OPU+8 (p &lt; 0.001), OPU+10 (p &lt; 0.001) and OPU+14 (p &lt; 0.001), with positive correlations between P4 level and hCG dose. Groups compared individually showed significant difference in P4 between low and high trigger dose at OPU+4 group 1 and 3 (p = 0.037) and OPU+8 group 1 and 3 (p = 0.007) and between all the three groups around implantation at OPU+6 group 1 and 2 (p = 0.011), group 2 and 3 (p = 0.042) and group 1 and 3 (p &lt; 0.001). Higher P4 levels around implantation were related to follicle count and to pregnancy. After logistic regression analyses there were still significant individual differences between the groups. Limitations, reasons for caution Although patients were randomized and strict inclusion and exclusion criteria were used, the RCT was un-blinded, including a relatively small number of patients. Moreover, for dosing purposes urinary hCG as well as recombinant hCG was used and pharmacokinetics differ. Finally, the P4 level could be influenced by circadian fluctuations. Wider implications of the findings This is the first study to explore dose-responses in circulating P4 after hCG trigger in IVF patients. Increasing the hCG trigger dose increased the endogenous P4 around peri-implantation. Personalizing the hCG trigger dose could be a key point to secure the most optimal P4 mid-luteal phase P4 level. Trial registration number Eudract 2013-003304-39

Expression of tissue inhibitor of metalloproteinases-1 in the human corpus luteum after luteal rescue

1996 ◽  
Vol 148 (1) ◽  
pp. 59-67 ◽  
Author(s):  
W C Duncan ◽  
A S McNeilly ◽  
P J Illingworth
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Proteolytic Enzymes ◽  
Specific Inhibitor ◽  
Northern Blotting ◽  
Corpora Lutea ◽  
Tissue Inhibitor Of Metalloproteinases ◽  
Tissue Inhibitor ◽  
Tissue Remodelling ◽  
Human Corpus Luteum

Abstract Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a specific inhibitor of a group of proteolytic enzymes known as matrix metalloproteinases. These enzymes have been widely implicated in the process of tissue remodelling. Extensive remodelling occurs in the corpus luteum during luteolysis unless human chorionic gonadotrophin (hCG) is produced by the early conceptus. This study aimed to investigate the expression and localisation of TIMP-1 in human corpora lutea during the luteal phase of the cycle and after luteal rescue with exogenous hCG to mimic the changes of early pregnancy. Human corpora lutea from the early (n = 4), mid- (n=4) and late (n=4) luteal phases and after luteal rescue by hCG (n=4) were obtained at the time of hysterectomy. Expression of TIMP-1 was investigated in these tissues by Western blotting, immunohistochemistry, Northern blotting and in situ hybridisation. Luteal cells of thecal origin were distinguished from those of granulosa origin by immunostaining for 17α-hydroxylase. A 30 kDa protein consistent with TIMP-1 was detected in human corpora lutea. This protein was localised to the granulosa lutein cells in all tissues examined. TIMP-1 mRNA was found in large quantities in all glands examined and this again localised to the granulosa lutein cells. The expression and localisation of TIMP-1 did not change throughout the luteal phase and was not altered by luteal rescue. The function of this uniform expression of TIMP-1 in the corpus luteum is not clear but these data suggest that the inhibition of structural luteolysis during maternal recognition of pregnancy is not mediated by regulation of TIMP-1 expression. Journal of Endocrinology (1996) 148, 59–67

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