Comparison of bovine uterine horns for progesterone and oxytocin levels with bilateral corpus luteum

1996 ◽  
Vol 76 (3) ◽  
pp. 463-464 ◽  
Author(s):  
W. A. Cerbito ◽  
M. P. B. Wijayagunawardane ◽  
M. Takagi ◽  
K. Sato ◽  
A. Miyamoto ◽  
...  

Bovine uterine horns with both ovaries containing a corpus luteum (CL) were compared for progesterone (P4) and oxytocin (OT) concentrations during the luteal phase of the estrous cycle. Uterine tissue samples from five Holstein cows with bilateral CL obtained from the slaughterhouse were used for this study. No significant difference was observed in P4 and OT levels in the right and left horns with corpora lutea in both ovaries. The data clearly indicate that both sides of the uterine horn having a functional CL are exposed to similar levels of P4 and OT, supporting the hypothesis that luteal products are delivered locally to the uterus. Key words: Progesterone, oxytocin, uterine horn, bilateral, corpus luteum, cow

2003 ◽  
Vol 83 (3) ◽  
pp. 487-492
Author(s):  
C. R. Christensen ◽  
M. J. Redmond ◽  
B. Laarveld

Primiparous sows were vaccinated against follistatin to determine the effect on ovulation rate following typical commercial estrus induction and synchronization. Seventy-five gilts received four vaccinations against a recombinant porcine follistatin (FS) or a sham vaccine (CTL). At 85 kg, gilts were induced into estrus with a combination of PG600 and hCG and synchronized using PGF2α. At the second estrus, antibody titers ranged from 0 to1:6400 in the FS-vaccinated treatment group and no FS antibodies were detected in the CTL group. Late in the second subsequent luteal phase the reproductive tracts of the gilts that had displayed two estruses were collected. There was no significant difference in the number of corpora lutea (FS = 13.2 ± 0.5, CTL = 14.5 ± 0.7) or corpora albicantia (FS = 12.1 ± 1.9, CTL = 12.3 ± 2.0) between treatments. Follistatin-vaccinated gilts displayed an increased number of luteal structures which resembled corpora hemorrhagica (P = 0.04). This study shows that vaccination of gilts against FS concurrent with estrus induction and synchronization affected ovarian morphology, although an effect on ovulation rate was not apparent. Key words: Swine, follistatin, immunoneutralization, fecundity, ovulation rate


1969 ◽  
Vol 60 (4) ◽  
pp. 603-610 ◽  
Author(s):  
R. T. Duby ◽  
J. W. McDaniel ◽  
C. H. Spilman ◽  
D. L. Black

ABSTRACT At least half of one uterine horn is required for normal regression of the corpora lutea in the pseudopregnant hamster. Although removal of any portion of the uterus slightly increased the duration of pseudopregnancy, only unilateral hysterectomy or unilateral hysterectomy and removal of the contralateral ovary did so significantly (P < 0.05). The presence of a sterile horn did not influence foetal development in the contralateral horn. No differences were observed in corpus luteum size between the right and left ovaries of animals unilaterally hysterectomized or unilaterally pregnant. Normal oestrous cycle activity continued following transplantation of the ovaries to the cheek pouches and pseudopregnancies were of normal duration. It is concluded from these observations that the amount of uterine tissue is of greater importance in regulating luteal regression in the hamster than its anatomical relationship to the ovary.


1987 ◽  
Vol 112 (2) ◽  
pp. 317-322 ◽  
Author(s):  
J. E. Sánchez-Criado ◽  
K. Ochiai ◽  
I. Rothchild

ABSTRACT Adult female rats were hypophysectomized and their pituitary glands autotransplanted beneath the left kidney capsule on day 2 (day 1 was the day of ovulation). In such rats the pituitary secretes prolactin fairly constantly and the corpora lutea secrete progesterone for several months. To induce the luteolytic effect of prolactin the rats were first injected s.c. with 2-bromo-α-ergocryptine (CB-154) on cycle days 12, 13 and 14 (i.e. 10, 11 and 12 days after operation) to depress prolactin secretion, and then with CB-154 vehicle (70% ethanol) daily until cycle day 21, to allow prolactin secretion to resume. One ovary was removed from each rat on day 15 and the remaining one on day 22. The mean (± s.e.m.) weight of the corpora lutea on day 15 was 1·46±0·06 mg and 0·98±0·07 mg on day 22 (n = 17). In contrast, rats in which the CB-154 treatment was maintained to day 21 had corpora lutea which weighed 1·31 ±0·09 on day 15 and 1·47 ±0·08 mg on day 22 (n = 15). To investigate whether indomethacin, a prostaglandin synthesis inhibitor, affected the luteolytic action of prolactin, the experiment was repeated, but on day 15 (after the removal of one ovary) the groups in which CB-154 treatment was stopped, as well as the group in which CB-154 treatment was maintained, were each divided into two groups. In one, indomethacin-containing silicone elastomer wafers and, in the other, blank silicone elastomer wafers, were placed within the bursa of the remaining ovary. There were no differences in corpus luteum weight on day 15 among any of these groups and the two groups of the first experiment. There was no significant difference in corpus luteum weight between day 15 and day 22 in any of the six groups except for the two groups treated with the CB-154 vehicle and not with indomethacin. Thus, treatment with indomethacin prevented the fall in corpus luteum weight associated with the discontinuation of CB-154 treatment. Serum prolactin levels fell until day 15 in all rats and remained low in those in which the CB-154 treatment was maintained to day 21, but returned to control values in those treated with vehicle after day 14. Serum progesterone levels fell and remained low in all groups. Indomethacin treatment had no effect on the levels of either serum prolactin or progesterone. We conclude that some of the pharmacological effects of indomethacin are to prevent prolactin-induced luteolysis, and we suggest that prolactin induces rapid regression of the corpus luteum by stimulating intraluteal prostaglandin production or by being necessary for the effect of luteolytic prostaglandins. J. Endocr. (1987) 112, 317–322


1997 ◽  
Vol 45 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Firyal S. Khan-Dawood ◽  
Jun Yang ◽  
M. Yusoff Dawood

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.


1995 ◽  
Vol 7 (3) ◽  
pp. 303 ◽  
Author(s):  
RT Gemmell

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.


Author(s):  
Vinny Dodiyar ◽  
Parkash Singh Brar ◽  
Narinder Singh ◽  
Mrigank Honparkhe

Background: Understanding of ovarian follicular dynamics and endocrine regulation is essential to design and use interventions to optimize reproductive efficiency. Bos indicus and Bos taurus cows have some differences in their follicular dynamics and ovarian steroidal hormones. The present study was planned to understand follicular dynamics vis-a-vis ovarian steroids profiles in Sahiwal cattle. Methods: The study was conducted in normal cyclic, pluriparous, non-lactating Sahiwal cows (n=7). Trans-rectal ultrasonography was performed to record the location, size, number of follicles and size of corpus luteum (CL) from the beginning, till the end of experiment. The dataset was used to characterize the follicular wave emergence, growth, regression, time of selection and ovulation of the dominant follicle in each cow. Result: Three Sahiwal cows showed two wave and four cows showed three wave estrous cycles with mean interovulatory length of 20.33±0.33 and 22.50±0.28 days, respectively. No significant difference was recorded in the maximum diameter of corpus luteum, P4 and E2 plasma levels between 2-wave and 3-wave estrous cycles. The peak progesterone values of 6.00±0.91 and 6.2±1.2 ng/ml and peak estradiol values of 15.83±0.60 and 14.31±0.44 ng/ml were recorded in 2-wave and 3-wave estrous cycle, respectively. The results showed that Sahiwal cows had 2-wave and 3-wave estrous cycle and the 3-wave estrous cycle had comparatively longer inter-ovulatory period and smaller maximum diameter of second wave dominant follicle than 2-wave estrous cycle.


1996 ◽  
Vol 148 (1) ◽  
pp. 59-67 ◽  
Author(s):  
W C Duncan ◽  
A S McNeilly ◽  
P J Illingworth

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


During the luteal phase of the cycle in many mammals, notably in the rabbit, ferret, and dog, the uterus undergoes changes which are designed to facilitate the implantation of the fertilised ovum. In other animals, such as the guinea-pig(5), the uterine changes during the luteal phase are histologically less obvious, but physiologically the uterine mucosa is in a peculiar condition of irritability. Injury to the mucosa at this time results in the production of large blocks of decidua-like tissue, to which the terms placentomata or deciduomata have been given. It has been shown by Marshall, Hammond, Loeb and others that the presence of the corpus luteum is essential for these post-ovulative uterine changes, and therefore that the corpus luteum is directly or indirectly responsible for their production. In the rabbit decidual tissue can only be induced to develop when functional corpora lutea are present in the ovary. In the guniea-pig (Loeb, 5) placentomata can be produced during the post-ovulation phase of the cycle in the unmated female, but in the rat Long and Evans (6) were unable to obtain a similar result. This discrepancy is undoubtedly due to the fact that in the short diœstrous cycle of the rat the corpora lutea undergo comparatively little development, whereas in the guinea-pig the cycle is longer and the corpora luteá are known to become active. During the pseudo-pregnancy which follows sterile copulation in the rat (Long and Evans, 6) and also during lactation (Corner and Warren, 2) placentomata can be produced. During both of these times corpora lutea develop to a greater extent than during the diœstrous cycle and become functional.


2010 ◽  
Vol 22 (1) ◽  
pp. 159
Author(s):  
T. E. Baby ◽  
P. M. Bartlewski

Ovarian antral follicles in sheep grow in an orderly succession, producing typically 3 to 4 follicular waves per 17-day estrous 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 estrous cycle, the time between the first 2 FSH peaks and days of wave emergence is longer than the intervals separating the ensuing FSH peaks and follicular waves. The prolonged inter-peak/inter-wave interval occurs early in the luteal phase when low levels of progesterone are secreted by developing, or non-fully functional, corpora lutea. 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 6 cycling Rideau Arcott × Dorset ewes from Day 0 (ovulation) to Day 4 (the mean duration of the inter-wave interval); 6 animals served as controls. Follicular growth was monitored in all animals by daily transrectal ultrasonography (Days 0 to 9). Jugular blood samples were drawn twice a day from Day 0 to 4 and then daily until Day 9 to measure systemic concentrations of P4 and FSH. The first FSH peak post-ovulation was detected on Day 1.4 ± 0.2 and 4.0 ± 0.2 in treated and control ewes, respectively (P < 0.05). The next FSH peak(s) occurred on Days 3.4 ± 0.3 and 5.2 ± 0.2 in the treatment group and on Day 5.5 ± 0.3 in controls. Consequently, the treatment group had, on average, 3 follicular waves emerging on Days 0, 3, and 6, whereas the controls produced 2 waves emerging on Days 0 and 5 (P < 0.05).We then retrospectively analyzed and compared daily serum concentrations of P4 and FSH obtained in cyclic Western White Face ewes (Columbia × Rambouillet) that had 3 (n = 10) or 4 (n = 19) follicular waves per cycle. Mean P4 concentrations were greater (P < 0.05) in sheep with 4 waves per cycle compared with their counterparts, which had 3 waves of follicular growth. Interestingly, the ewes with 3 waves exceeded (P < 0.05) all animals with 4 follicular waves in mean serum FSH concentrations on Days 0 to 2, 6 to 7, and 9 to 15 post-ovulation. In summary, creation of mid-luteal phase levels of P4 in metestrus shortened the time to the first post-ovulatory FSH peak in ewes, resulting in emergence of one more follicular wave compared with control animals during the same time frame. The ewes exhibiting 4 waves of follicular emergence had greater serum levels of P4 but lower FSH concentrations compared with sheep with 3 waves per cycle. Therefore, progesterone appears to be a key endocrine signal governing the control of periodic increases in serum FSH concentrations and the number of follicular waves in cyclic sheep. This study was funded by OMAFRA and NSERC grants. Appreciation is extended to Norman C. Rawlings, Susan Cook, and Sekallu Srinivas (University of Saskatchewan) and the staff at Ponsonby Sheep Research Station.


1958 ◽  
Vol 17 (3) ◽  
pp. 248-260 ◽  
Author(s):  
R. A. BEATTY

SUMMARY The numbers of corpora lutea and the numbers and sizes of 6-day blastocysts have been studied in rabbits, widely varying in ages and weights, that had been subjected to a superovulation treatment. For all does, the average value of each characteristic on the left sides of the animals was similar to that on the right, the average left-to-right difference being not significant. An average of thirty-one corpora lutea and thirteen blastocysts per doe was obtained. Maximum numbers per doe were one hundred and fifty-three corpora lutea and seventy-three blastocysts. Average blastocyst diameter was 2·203 mm, the average volume being 6·780 mm3. There was a fairly large variation from one doe to another in the relative numbers of corpora lutea (or in the relative numbers of blastocysts) on the two sides of the animal. The number of blastocysts per doe was positively related to the number of corpora lutea. The number of corpora lutea per doe was inversely related to the age of the doe. An inverse relation between the number of blastocysts and the age of the doe was presumably indirect, being mediated by the number of corpora lutea. All these relationships were highly significant. There was no demonstrable relationship between the number of corpora lutea and the weight of the doe. No firm evidence was found for a direct relationship (independent of weight and number of corpora lutea) between the number of blastocysts and age, or for any relationship with weight. Diameter of blastocysts seemed more appropriate than volume as a measure of size suitable for analysis. Transformations tending to give linear relationships between variables have been studied. Size differences between blastocysts within the same uterine horn formed a large source of variation, probably not attributable to the superovulation procedure. Differences in blastocyst size between uterine horns within does were significant but introduced little extra variation. Mean blastocyst size varied greatly from one doe to another, but none of this variation was related significantly to known factors such as the weight of the dam or sire, or the age of the dam. The experiment appeared to be fairly sensitive in detecting these relationships. The relationships found between the number of corpora lutea and the age or weight of the doe can be reconciled with the previous literature. The lack of demonstrable connexion between blastocyst size and the weight of dam or sire is in conflict with the results of other authors, and no specific reconciliation can be made. It is suggested that uniformity in age is more important than uniformity in weight when test animals are selected for assay of follicle stimulating hormone under conditions comparable with those of the present work.


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