scholarly journals Effect of immunization against the alpha N (alphaN) and alpha C (alphaC) peptides of the alpha43 subunit of inhibin on antral follicular growth and atresia and the patterns of gonadotrophin secretion in ewes

Reproduction ◽  
2001 ◽  
pp. 707-718 ◽  
Author(s):  
A Dhar ◽  
BW Doughton ◽  
E Pruysers ◽  
RW Brown ◽  
JK Findlay

The aims of this study were to investigate the role of inhibin in the distribution of healthy and atretic antral follicles and the secretion patterns of gonadotrophins. Ewes were actively immunized against either alphaN or alphaC of the inhibin alpha subunit with a primary injection and three booster injections. The control ewes received adjuvant only. The ovaries were removed either before or at 24 h after hCG administration in a synchronized follicular phase 48 h after removal of intravaginal progesterone pessaries. Morphological observations were made on every fifth section of the complete ovary (one per ewe) stained with haematoxylin and eosin. The mean number of corpora lutea observed per ewe with corpora lutea was not significantly different in ewes immunized against alphaN (2.4; alphaN-immunized ewes) or alphaC (2.6; alphaC-immunized ewes), and control (2.4) ewes, although some corpora lutea appeared cystic in the immunized ovaries. Compared with luteal phase concentrations, mean basal FSH concentrations in the early follicular phase were significantly increased in the alphaC-immunized ewes, similar in alphaN-immunized ewes and reduced in control ewes. No differences were observed in any of the LH parameters. Before hCG treatment, healthy antral follicles > 1 mm in diameter were not observed in any of the 52 follicles in the aC-immunized ewes and were observed in one of 37 follicles from alphaN-immunized ewes compared with 19 of 28 follicles in control ewes (P < 0.0001). For healthy antral follicles < 1 mm in diameter, there were 72 of 85 follicles in the alphaC-immunized ewes, 79 of 81 follicles in the alphaN-immunized ewes and 81 of 82 follicles in the control ewes. Similar results were obtained in healthy antral follicles < 1 mm in diameter at 24 h after hCG administration. In contrast to the control ewes, no healthy preovulatory follicles (> 6 mm in diameter) were observed in alphaN- and alphaC-immunized ewes either before or 24 h after hCG administration. Two newly formed corpora lutea from alphaC-immunized ovaries contained retained oocytes compared with none in control and alphaN-immunized ovaries. In conclusion, immunization against alphaN and alphaC may result in disruption of the normal processes of antral follicular growth and maturation independent of the concentrations of FSH and LH.

Reproduction ◽  
2002 ◽  
pp. 527-533 ◽  
Author(s):  
H Cardenas ◽  
WF Pope ◽  

Treatment with testosterone increases ovulation rate in pigs. The present study was conducted to examine the effects of 5alpha-dihydrotestosterone (DHT), a non-aromatizable androgen receptor ligand, on ovulation rate and amounts of androgen receptor and FSH receptor mRNAs in postpubertal gilts. In Expt 1, ovulation rate in response to daily i.m. injections of 0, 6, 60 or 600 microg DHT kg(-1) body weight from day 13 of the oestrous cycle (day 0 = day 1 of oestrus) to the following oestrus increased with each dose of DHT (P < 0.05). The mean increase in number of corpora lutea ranged from approximately three to 17 over the three dosages of DHT. In Expt 2, gilts treated daily with 60 microg DHT kg(-1) body weight during the early follicular phase (from day 13 to day 16), coincident with follicular recruitment, or the late follicular phase (day 17 to oestrus), had higher (P < 0.05) rates of ovulation compared with gilts that received vehicle, and were not different from gilts treated with DHT from day 13 to oestrus. Percentage recovery of day 3 embryos was not altered when gilts were treated from day 13 to day 16 or from day 17 to oestrus; however, treatment of gilts with DHT from day 13 to oestrus decreased recovery of day 3 (Expt 1) or day 11 (Expt 2) conceptuses. Daily administration of 6 microg DHT kg(-1) body weight to gilts from day 13 of the oestrous cycle to the following oestrus (Expt 3) did not affect the relative amounts of androgen receptor mRNA, but increased (P < 0.05) the amounts of FSH receptor mRNA in preovulatory follicles as determined by RT-PCR. The results of these experiments indicate that androgens may regulate ovulation rate in gilts. One of the roles of androgens might be regulation of the amounts of FSH receptor mRNA in ovarian follicles.


Reproduction ◽  
2014 ◽  
Vol 148 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Eugenia Mercedes Luque ◽  
Pedro Javier Torres ◽  
Nicolás de Loredo ◽  
Laura María Vincenti ◽  
Graciela Stutz ◽  
...  

In order to clarify the physiological role of ghrelin in gestation, we evaluated the effects of administration of exogenous ghrelin (2 or 4 nmol/animal per day) or its antagonist (6 nmol/animal per day of (d-Lys3)GHRP6) on fertilization, early embryo development, and implantation periods in mice. Three experiments were performed, treating female mice with ghrelin or its antagonist: i) starting from 1 week before copulation to 12 h after copulation, mice were killed at day 18 of gestation; ii) since ovulation induction until 80 h later, when we retrieved the embryos from oviducts/uterus, and iii) starting from days 3 to 7 of gestation (peri-implantation), mice were killed at day 18. In experiments 1 and 3, the antagonist and/or the highest dose of ghrelin significantly increased the percentage of atrophied fetuses and that of females exhibiting this finding or a higher amount of corpora lutea compared with fetuses (nCL/nF) (experiment 3: higher nCL/nF-atrophied fetuses: ghrelin 4, 71.4–71.4% and antagonist, 75.0–62.5% vs ghrelin 2, 46.2−15.4% and control, 10–0.0%;n=7–13 females/group;P<0.01). In experiment 2, the antagonist diminished the fertilization rate, and both, ghrelin and the antagonist, delayed embryo development (blastocysts: ghrelin 2, 62.5%; ghrelin 4, 50.6%; and antagonist, 61.0% vs control 78.4%;n=82–102 embryos/treatment;P<0.0001). In experiment 3, additionally, ghrelin (4 nmol/day) and the antagonist significantly diminished the weight gain of fetuses and dams during pregnancy. Our results indicate that not only hyperghrelinemia but also the inhibition of the endogenous ghrelin effects exerts negative effects on the fertilization, implantation, and embryo/fetal development periods, supporting the hypothesis that ghrelin (in ‘adequate’ concentrations) has a physiological role in early gestational events.


2016 ◽  
Vol 28 (2) ◽  
pp. 248
Author(s):  
K. Center ◽  
D. Dixon ◽  
R. Rorie

A study investigated the use of anti-Müllerian hormone (AMH) and/or follicle counts as a predictor of subsequent superovulatory response and embryo production in 79 beef cows. Before initiation of superovulation, ultrasonography was used to scan the ovaries of each donor cow to record the number of 3 to 5 mm follicles present, and a blood sample was collected for measure of serum AMH. At the time of embryo collection, the ovaries of donor cows were palpated to estimate the number of corpora lutea (CL) present on each ovary. Recovered embryos were evaluated for stage of development and morphological quality. Across cows, serum AMH ranged from 0.013 to 0.898 ng mL–1, with a mean of 0.293 ng mL–1. The distribution of AMH concentrations was divided into quartiles (AMH Q1 through Q4, with Q1 the lowest and Q4 the highest, ng mL–1) for analysis (ANOVA). Number of donors/collections in AMH Q1 through Q4 was 26, 22, 24, and 24, respectively. Donor cows in AMH Q4 had a greater (P < 0.001) number of 3- to 5-mm follicles at the start of superovulation than did donors in either Q1 or Q2. At embryo collection, cows in AMH Q3 and 4 had more (P < 0.001) palpable CL than cows in AMH Q1. The mean number of embryos recovered from donor cows in AMH Q4 (20.1 ± 1.8) was greater (P < 0.001) than those recovered from cows in either AMH Q1 (9.8 ± 1.8) or 2 (9.4 ± 1.9), but similar to that of AMH Q3 (15.5 ± 1.8). Percentages of recovered embryos classified as transferrable, degenerate, or unfertilized were similar (P ≥ 0.275) across AMH quartiles. Analysis indicated that AMH was positively correlated (P < 0.001) with mean follicles (r = 0.458), CL (r = 0.452), and embryos recovered (r = 0.430). To determine if follicle counts at the start of superovulation are predictive of superovulatory response, the distribution of follicle counts was divided into quartiles (F Q1 through Q4, with Q1 the lowest and Q4 the highest) for analysis. Donor cows with higher follicle counts (F Q3 and 4) at the start of superovulation had more (P < 0.001) palpable CL at embryo collection than donor cows in F Q1 or 2. More (P < 0.001) embryos (20.0 ± 2.2 v. 9.6 ± 1.8 and 11.6 ± 1.6) were recovered from cows with the highest follicle counts (F Q4) compared with cows having lower (F Q1 and 2) follicle counts, respectively. The percentage of transferable embryos and unfertilized ova were similar (P ≥ 0.688) across follicle count quartiles. As was noted for AMH, mean number of follicles at the start of superovulation was positively correlated (P < 0.001) with mean CL (r = 0.556) and mean embryos (r = 0.423) but not percentages of viable or degenerate embryos or unfertilized oocytes (P ≥ 0.153). Results confirm that relative AMH concentration was positively correlated with number of small antral follicles in the ovaries of cows and might be used to either predict superovulatory response or possibly adjust superovulatory regimen to improve superovulatory response. Further study is needed to determine the effectiveness of using either AMH concentration or follicle counts to adjust superovulatory regimens.


1977 ◽  
Vol 85 (1) ◽  
pp. 177-188 ◽  
Author(s):  
Sten Jeppsson ◽  
Gunnar Rannevik ◽  
Jan I. Thorell

ABSTRACT A longitudinal study of basal plasma LH and FSH and their responses to 25 μg LRH iv as well as basal levels of oestradiol, progesterone, prolactin and HCG was performed every week in 3 women, pregnant after heterologous insemination, from conception until the 6th week of gestation. A comparative study was carried out in 7 women in cycles in which no conception occurred after insemination. All hormones were assayed with radioimmunoassay. LH was measured with a specific assay for native LH, which did not cross-react with HCG. A decrease in basal levels of LH and FSH as well as decreasing responses to LRH was found during the first 2 weeks of gestation. These changes did not differ from what was observed during the luteal phase in the non-conception cycles. One week later the basal FSH levels and the FSH response in the pregnant women showed a further decrease, while in the non-pregnant women, now reaching the early follicular phase, a rise in FSH basal levels occurred. The basal levels of LH and the LH response, however, did not differ from that found in the nonpregnant women at this time. FSH basal levels remained below the lower normal limit in eumenorrhoic women from the 3rd week of gestation. By this time the FSH response was almost completely inhibited. The LH basal levels, however, remained above the lower normal limit in eumenorrhoic women, but the LH response to LRH progressively decreased and was completely inhibited by the 5th week of gestation. In the non-conception cycles the LH response varied with the levels of oestradiol in plasma. This was not found in the pregnant women as the decrease in gonadotrophin response occurred while oestradiol remained at mid-cycle levels during the first 4 weeks of gestation. Rather it seems that the increasing and continuously elevated level of progesterone, in the presence of appropriate levels of oestradiol, might be the main go nadal steroid responsible for the diminishing pituitary secretion. The contribution of HCG to the further decrease in gonadotrophin secretion after the 2nd week of pregnancy cannot be answered by the present studies. Prolactin remained at non-pregnant levels until the 6th week of gestation, and appeared to have no influence on the secretion of gonadotrophins during early pregnancy.


Reproduction ◽  
2017 ◽  
Vol 153 (2) ◽  
pp. 233-240 ◽  
Author(s):  
Kenneth P McNatty ◽  
Derek A Heath ◽  
Zaramasina Clark ◽  
Karen Reader ◽  
Jennifer L Juengel ◽  
...  

Ewes heterozygous for combinations of the Inverdale (FecXI; I+), Booroola (FecB; B+) and Woodlands (FecX2W; W+) mutations have ovulation rates higher than each mutation separately. The aims of the experiments described herein were to examine the ovarian phenotypes in I+B+ and I+B+W+ ewes and to compare these with the appropriate ++ (controls), I+ and BB animals available for this study. The mean ± s.e.m. ovulation rates in the ++ (n = 23), I+ (10), I+B+ (7), I+B+W+ (10) and BB (3) animals were 1.8 ± 0.1, 2.5 ± 0.2, 6.6 ± 1.0, 9.6 ± 0.9 and 9.7 ± 0.9 respectively. The maximum number of granulosa cells per follicle in the ++ and I+ genotypes was accumulated after exceeding 5 mm diameter, whereas in I+B+, I+B+W+ and BB animals, this was achieved when follicles reached >2–3 mm. The number of putative preovulatory follicles, as assessed from those with LH-responsive granulosa cells, 24 h after the induction of luteolysis, was higher (P < 0.01) in the I+B+ and I+B+W+ compared to the ++ and I+ genotypes. The median follicular diameters of these follicles in the ++, I+, I+B+, I+B+W+ and BB genotypes were 6, 5, 3, 3 and 3 mm respectively. The total number of granulosa cells in the putative preovulatory follicles when added together, and total mass of luteal tissue, did not differ between the genotypes. Thus, despite large ovulation rate differences between animals with one or more fecundity genes, the total cell compositions over all preovulatory follicles and corpora lutea, when added together, are similar to that from the one or two such follicles in the wild types.


1987 ◽  
Vol 114 (2) ◽  
pp. 171-177 ◽  
Author(s):  
Gunnar Selstam ◽  
Ensio Norjavaara ◽  
Sten Rosberg ◽  
Knut Nordenström ◽  
Jan-Erik Damber ◽  
...  

Abstract. The subject of the study was the development of follicular and luteal catecholamine responsiveness during the periovulatory period. Follicles and corpora lutea and granulosa cells were obtained from the PMSG ovulatory model and adenylate cyclase activity measured in membrane fractions. In the earlier part of the follicular phase (48 h and 26 h before ovulation) no response to noradrenalin on follicular and granulosa cell adenylate cyclase activity was seen. A small but significant response to noradrenalin was observed from 18 h before until 3 h after ovulation. The response to noradrenalin on luteal adenylate cyclase activity increased markedly with time and reached a maximum 39–57 h after ovulation. After this time the luteal response to noradrenalin decreased with luteal age. The effect of LH was less than that of noradrenalin during the early luteal phase, and in contrast to noradrenalin, increased with luteal age. The combined effects of LH and noradrenalin were not additive. In order to test whether gonadotropins could induce a noradrenalin response, injections of LH and FSH were given to the animals two days before ovulation. LH, but not FSH, induced a small but significant response to noradrenalin 16 h later. The present investigation has shown that ovarian responsiveness to catecholamines appears in preovulatory follicles followed by a marked increase in luteal catecholamine responsiveness. This development could at least partly occur under the influence of LH.


2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Anton Budhi Darmawan ◽  
Marsetyawan H. N. E. Soesatyo ◽  
Ratna Dwi Restuti ◽  
Agus Surono

Background. Chronic suppurative otitis media (CSOM) is a common public health problem worldwide and a major cause of hearing impairment especially in developing countries. The role of Mannose-Binding Lectin (MBL), a component of innate immunity, in CSOM has not been studied. The aim of the study was to examine whether MBL deficiency was more frequently present in cases group of tubotympanic CSOM patients rather than healthy subjects. Material and Methods. This was an analytic observational study. Subjects were enrolled in the Otorhinolaryngology Clinic at Margono Soekarjo Hospital, Purwokerto, Indonesia. An independent t-test was used to compare the mean of MBL serum concentration between tubotympanic CSOM subjects and control. Results. From 36 tubotympanic CSOM patients, there were 8 (22.22%) patients with MBL deficiency (MBL level < 100 ng/ml), while no deficiency was found in the control group. The mean of MBL level in cases group was 354.88 ng/ml, with the lowest level being 0.001 ng/ml and the highest level 690.24 ng/ml, while in the control group MBL level mean was 376.27 with the lowest level being 188.71 and the highest level 794.54 ng/ml. Conclusion. There was no significant difference of MBL serum level between tubotympanic CSOM and control group. However, the presence of subjects with MBL deficiency in the tubotympanic CSOM group might be considered as playing a role in the tubotympanic CSOM.


2002 ◽  
Vol 173 (2) ◽  
pp. 297-304 ◽  
Author(s):  
MJ Engelbregt ◽  
MM van Weissenbruch ◽  
C Popp-Snijders ◽  
HA Delemarre-van de Waal

In the present study we examined the consequences of intrauterine growth retardation and postnatal food restriction on the maturational process of sexual development by studying onset of first cycle. In addition, we investigated the effect of pregnant mare serum gonadotropin (PMSG) on ovarian growth and ovulation in intrauterine growth-retarded (IUGR) and postnatally food-restricted (PFR) rats. Intrauterine growth retardation was induced by uterine artery ligation on day 17 of gestation and food restriction was achieved by enlarging the litter to 20 pups per mother from day 2 after birth until weaning (day 24). In control rats, vaginal opening and the first cycle took place on the same day. In IUGR rats, uncoupling occurred between vaginal opening and the first cycle. Vaginal opening was delayed (P<0.05) and the first cycle was even further delayed (P<0.01) compared with controls. Body weight in IUGR rats was lower (P<0.05) at vaginal opening, but at first cycle and after stimulation with 50 IU PMSG in the first cycle it was similar to that in controls. In the ovaries of IUGR rats, the numbers of primordial (P<0.05), growing (P<0.01) and antral follicles (P<0.01), and the total number of follicles (P<0.01) were lower than in controls after stimulation with 50 IU PMSG at first cycle. The number of corpora lutea in the ovaries of the IUGR rats and the controls was similar and reflected superovulation. In the PFR rats, vaginal opening occurred at the same time as in control rats, but at a lower body weight (P<0.01). First cycle was much delayed (P<0.01), by which time body weight was greater (P<0.01) than that of controls at first cycle. On the basis of the differences in weight and age between PFR rats and controls at first cycle, we performed two studies. In study A, ovaries were analysed histologically 42 h after stimulation with PMSG at first cycle of control rats and age-matched PFR rats. In study B, the ovaries of PFR rats at first cycle and age-matched control rats were examined 42 h after PMSG stimulation. In the ovaries of the PFR rats in study A, a greater total number of follicles (P<0.05) was observed, represented by a greater number of primordial follicles (P<0.01) and a lower number of antral follicles (P<0.05), including corpora lutea. The number of corpora lutea in the ovaries of the PFR rats was significantly lower than that in controls (P<0.01). The total number of follicles in the ovaries of the PFR rats of study B did not differ from the age-matched controls after PMSG stimulation at first cycle, and neither did the number of the follicles in the different classes. We conclude that, in IUGR rats at first cycle, PMSG can induce multiple follicular growth and development followed by superovulation comparable to that in controls, despite a decreased total number of follicles in the ovaries. However, in PFR rats of the same age, the ovary is not capable of responding adequately to PMSG, despite a greater total number of follicles. Stimulation with PMSG at first cycle resulted in follicular growth and superovulation comparable to those in age-matched controls. Undernutrition in different critical time periods around birth in the rat leads to ovarian development in such a way that, in both groups, an increased risk of reduced reproductive capacity can be expected.


2019 ◽  
Vol 17 (1) ◽  
pp. 162-164
Author(s):  
Alexander Kostyuk

The role of scholarly conferences as a method of scholarly communications cannot be overestimated. Thus, Torgler and Piatti (2013) found that in 1974, only 19 per cent of papers published in American Economic Review had been presented at one or more conferences, workshops or seminars, for critical commentary prior to publication. On average, the number of presentations was 0.24 per paper. Twenty-five years later, 73 percent of the papers accepted for publication have been previously presented, and the mean number of pre-publication presentations was 4.73. Personal editorial and reviewing experience give a right to conclude that papers previously presented at the conferences have more serious scholarly content, solid empirical fundamentals and relevance. Scholarly journal reviewers are more favourable about such papers and it takes less time to receive the final approval of the reviewers for further publishing. Discussing the papers in an open manner at the conferences is welcome both by the authors of the papers as well as the commenting scholars adding more enthusiasm for further research. International conference "New Challenges in Corporate Governance: Theory and Practice"1 took place in Naples on October 3-4, 2019.2 About 80 experts from America, Europe, Asia, Africa and Oceania gathered at the conference venue to discuss relevant issues of corporate governance, ownership and control, share their most recent research and come up with the solutions of the existing corporate governance research.


2020 ◽  
Vol 7 (12) ◽  
pp. A563-569
Author(s):  
Deepa Sowkur Anandarama Adiga ◽  
Debarshi Saha ◽  
Karthick R G ◽  
Vishnu Priya M ◽  
Purnima S Rao ◽  
...  

Background: Megaloblastic anemias are macrocytic normochromic anemia with mean corpuscular volume (MCV) of 100 fl-140 fl and caused by deficiency of either cobalamin (vitamin B12) or folate. However, increased MCV is not specific for megaloblastic anemia, nor is Vitamin B12 assay by chemiluminescence. We undertook this study to evaluate the possible role of Volume, Conductivity and Scatter (VCS) of WBCs derived from standard hematology analyzer to indicate megaloblastic anemia. Methods: We performed a case control study comparing data of 60 patients with low serum vitamin B12 or folate levels with 60 healthy volunteers. Comparison of the volume, conductivity and scatter parameters for neutrophils and monocytes of cases and control were done. Result: The mean neutrophil volume of cases (158.37±18.13fl) was significantly higher (p= 0.0001) compared to controls (141.26±4.22fl). Similarly, mean monocyte volume of cases (183.34±16.90fl) was significantly (p=0.0001) higher compared to controls (166.55±8.66fl). The difference in the mean conductivity of both neutrophils and monocytes between cases and controls were insignificant (p=0.43). Conclusion: Our study suggests analysis of VCS parameters for neutrophils and monocytes was a simple and objective method that substantiates the existence of subclinical deficiency of vitamin B 12 and folate with fair degree of certainty.


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