Journal of reproduction and fertility. Supplement最新文献

{"title":"Involvement of immune cells in regulation of ovarian function.","authors":"J. L. Pate","doi":"10.1530/BIOSCIPROCS.3.028","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.3.028","url":null,"abstract":"Primary cultures of luteal cells have been used to determine both acute and chronic effects of cytokines on luteal cell function and viability. Gonadotrophin-stimulated progesterone production is inhibited by interleukin 1 beta (IL-1 beta), tumour necrosis factor alpha (TNF-alpha), or gamma-interferon (IFN-gamma), the last two cytokine being more effective than IL-1. In contrast, all three cytokines are potent stimulators of prostaglandin production by these cells. The mechanism by which prostaglandin synthesis is enhanced may differ slightly for each cytokine. In luteal cells, TNF-alpha appears to act primarily through stimulation of phospholipase A2, whereas IL-1 beta may activate phospholipase C and prostaglandin endoperoxide synthase (PGS) in addition to phospholipase A2. The mechanism of action of IFN-gamma has not yet been determined. In addition to the observed functional effects, cytokines may also promote cell death during luteal regression. Although the three cytokines mentioned have little or no effect on viability of cultured luteal cells when administered separately, combined treatment with TNF-alpha and IFN-gamma results in a substantial decrease in the number of viable cells. Inhibition of cytokine-stimulated prostaglandin production does not alter the cytotoxic effect of these cytokines. Expression of major histocompatibility (MHC) class I molecules on luteal cells is enhanced, and MHC class II molecules are induced, by exposure to IFN-gamma. This is especially intriguing, as MHC class II expression increases before luteal regression in vivo, and is suppressed in early pregnancy. In summary, evidence is rapidly accumulating that supports the hypothesis that the function or structural integrity of luteal cells may be modulated by resident immune cells. Future research will probably address how these local events are hormonally controlled, and if they can be modified to regulate corpus luteum function.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"64 1","pages":"365-77"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84410380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhibin and oestradiol in the control of FSH secretion in the sheep.","authors":"D. T. Baird, B. K. Campbell, George E Mann, A. McNeilly","doi":"10.1530/BIOSCIPROCS.2.010","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.2.010","url":null,"abstract":"In the sheep both FSH and LH are necessary for development of large antral follicles. The secretion of FSH is controlled by the negative feedback effect of two ovarian hormones, oestradiol and inhibin, acting at the level of the anterior pituitary. Both are derived from the granulosa cells of large antral follicles which are present in sheep ovaries throughout the oestrous cycle. FSH stimulates growth and mitosis and so the fully differentiated granulosa cells of the large preovulatory follicles acquire receptors for LH, have maximal aromatase activity and produce large amounts of inhibin. The number of these large antral follicles (oestrogenic) which have the potential for ovulation corresponds to the ovulation rate specific for each particular breed of sheep. Over 90% of the oestradiol secreted by the ovaries is derived from these chosen follicles. In contrast, inhibin (and androstenedione) is also secreted by large antral follicles which have lost or not yet acquired maximal aromatase activity. The secretion of oestradiol by the preovulatory follicle(s) is dependent on the supply of androgen precursors produced by the theca which is stimulated by LH. When the concentration of progesterone falls at the end of the luteal phase the increased secretion of LH stimulates the progressive increase in secretion of oestradiol which occurs during the follicular phase. At this stage of the cycle there is a modest inconsistent rise in inhibin, the secretion of which is not stimulated by LH but is related to the increase in the number of large antral follicles. It is suggested that inhibin with its long half-life sets the overall level of negative feedback while oestradiol is responsible for the day-to-day fluctuations in the concentration of FSH which determines the number of ovulatory follicles. This dual control of FSH is adapted to monitor both the total number of large antral follicles in the ovaries (inhibin) and the number which are selected for ovulation (oestradiol).","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"46 1","pages":"125-38"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76726079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nutrient effects on ovulation rate, ovarian function and the secretion of gonadotrophic and metabolic hormones in sheep.","authors":"Downing Ja, RJ Scaramuzzi","doi":"10.1530/BIOSCIPROCS.2.017","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.2.017","url":null,"abstract":"Nutrition is one of the most significant influences on the ovulation rate of sheep. In the extensive systems of husbandry practised in many countries most animals will experience at least one period of nutritional deprivation during their lifetime. Under these conditions reproductive performance is often sub-optimal, an effect usually attributed to poor nutrition. The effects of poor nutrition on reproductive performance are evident in many events in the reproductive cycle and the one which this paper will highlight is ovulation.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"97 1","pages":"209-27"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73387386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sexual behaviour of rams: male orientation and its endocrine correlates.","authors":"JA Resko, A. Perkins, CE Roselli, JN Stellflug, FK Stormshak","doi":"10.1530/BIOSCIPROCS.4.020","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.4.020","url":null,"abstract":"The components of heterosexual behaviour in rams are reviewed as a basis for understanding partner preference behaviour. A small percentage of rams will not mate with oestrous females and if given a choice will display courtship behaviour towards another ram in preference to a female. Some of the endocrine profiles of these male-oriented rams differ from those of heterosexual controls. These differences include reduced serum concentrations of testosterone, oestradiol and oestrone, reduced capacity to produce testosterone in vitro, and reduced capacity to aromatize androgens in the preoptic-anterior hypothalamus of the brain. Our observation that aromatase activity is significantly lower in the preoptic-anterior hypothalamic area of male-oriented rams than in female-oriented rams may indicate an important neurochemical link to sexual behaviour that should be investigated. The defect in steroid hormone production by the adult testes of the male-oriented ram may represent a defect that can be traced to the fetal testes. If this contention is correct, partner preference behaviour of rams may also be traceable to fetal development and represent a phenomenon of sexual differentiation.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"149 1","pages":"259-69"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86126049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative patterns of follicle development and selection in ruminants.","authors":"G. Adams","doi":"10.1530/BIOSCIPROCS.4.002","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.4.002","url":null,"abstract":"Expanding technological capabilities, particularly in ultrasonography and molecular endocrinology, have bridged the gap between form and function of the ovary, and have been a catalyst for intense research activity in this area during the last decade. However, the study of follicular dynamics is still in its infancy in ruminant species other than cattle, and controversy persists regarding the pattern of follicular growth and the existence of follicular dominance. The bovine model of ovarian function is presented as a foundation for concepts surrounding the control of follicular development in ruminants, and to place in context the results of recent studies in sheep, goats, muskoxen, cervids and camelids. This comparative approach is used to determine important generalities that appear to be applicable, as fundamental physiological phenomena, to all ruminant species. Although clear differences in follicular dynamics are evident, differences appear to be specific rather than general, and the following conclusions are consistent with results reported in ruminant species to date: (1) follicles grow in a wave-like fashion; (2) periodic surges in circulating FSH are associated with follicular wave emergence; (3) selection of a dominant follicle involves a decline in FSH and acquisition of LH responsiveness; (4) periodic anovulatory follicular waves continue to emerge until occurrence of an LH surge (that is, at the time of luteolysis during the ovulatory season or during transition from the anovulatory season); (5) within species, there is a positive relationship between the duration of the oestrous cycle and the number of follicular waves; (6) progesterone suppresses LH secretion and growth of the dominant follicle; (7) the duration of the interwave interval is a function of follicular dominance, and is negatively correlated with circulating FSH; (8) follicular dominance in all species is more pronounced during the first and last follicular waves of the oestrous cycle; and (9) pregnancy, the prepubertal period and seasonal anoestrus are characterized by regular, periodic surges in FSH and emergence of anovulatory follicular waves.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"27 1","pages":"17-32"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86555380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulation of gonadotrophin-releasing hormone secretion by testosterone in male sheep.","authors":"Hileman Sm, GL Jackson","doi":"10.1530/BIOSCIPROCS.4.018","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.4.018","url":null,"abstract":"In males, including the ram, testosterone, acting via its primary metabolites oestradiol and dihydrotestosterone (DHT), suppresses circulating LH concentrations. This effect is due primarily, although not totally, to decreased frequency of gonadotrophin-releasing hormone (GnRH) pulses. The arcuate-ventromedial region (ARC-VMR) of the mediobasal hypothalamus and possibly the medial preoptic area (mPOA) are sites at which oestradiol acts to suppress GnRH, but the site of DHT action is not known. Given that native GnRH neurones appear to contain few or no oestrogen or androgen receptors, the effects of testosterone metabolites probably are exerted by modulating activity of inhibitory interneurone systems such as beta-endorphin, dopamine, and gamma-aminobutyric acid (GABA). Although beta-endorphin clearly inhibits GnRH secretion, the observation that testosterone treatment during a long-day photoperiod reduced proopiomelanocortin (POMC) mRNA in the arcuate nucleus while coincidentally suppressing GnRH release indicates that beta-endorphin does not mediate the inhibitory effect of testosterone on GnRH. Activation of GABAA receptors in either the mPOA or ARC-VMR suppressed LH, whereas activation of GABAB receptors in the ARC-VMR increased LH pulse amplitude. Therefore, it is suggested that GABA acts in both regions to regulate LH. Whereas testosterone affects GABA metabolism in the rat hypothalamus, its effect in the ram hypothalamus is yet to be determined. Testosterone treatment activated dopaminergic cells in the retrochiasmatic A15 area in the same animals in which it suppressed POMC mRNA in the arcuate nucleus. This dopaminergic system may partially mediate the negative feedback effect of testosterone in the ram analogous to its role in partially mediating the negative effect of oestrogen in the ewe. Future studies must concentrate on determining how these and other putative inhibitory neuronal systems interact and how they in turn are regulated by environmental factors such as photoperiod.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"40 1","pages":"231-42"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83644436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The search for the Booroola (FecB) mutation.","authors":"G. Montgomery, J. Penty, E. Lord, M. Broom","doi":"10.1530/BIOSCIPROCS.3.009","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.3.009","url":null,"abstract":"Sheep derived from the Booroola Merino strain carry an autosomal mutation (FecB) that increases ovulation rate and litter size. One approach to characterize the genetic mutation is to locate the gene using positional cloning. The locus has been mapped to a region between genes for secreted phosphoprotein 1 (SPP1) and epidermal growth factor (EGF) on sheep chromosome 6. Analysis of possible candidate genes have excluded a number of genes associated with control of reproduction including genes from chromosome 6. Attempts to define close flanking markers and clone the region of DNA containing the mutation are now in progress. We have cloned additional markers and developed a linkage map showing that the FecB locus maps towards the centromere on chromosome 6. We have developed a yeast artificial chromosome (YAC) library for the sheep and begun screening the library to identify large DNA clones spanning the FecB region. These will be used to locate the mutation and shed light on how the mutation increases ovulation rate in Booroola sheep.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"60 1","pages":"113-21"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90919038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Control of luteal function during early pregnancy in sheep.","authors":"J. Martal","doi":"10.1530/BIOSCIPROCS.1.019","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.1.019","url":null,"abstract":"Prolactin and LH are required for the maintenance of normal luteal structures during early pregnancy in the ewe, whilst luteolysis, induced by prostaglandin F-2 alpha is inhibited by the presence of the conceptus. The trophoblast also secretes a local anti-luteolytic factor, trophoblastin, which is most probably a protein because it is thermolabile and inactivated by pronase. It is soluble at pH 9.6 and can be separated on Ultrogel. Trophoblastin is present for a short time (12th-22nd day of pregnancy) but its effect may last several months.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"22 1","pages":"201-10"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73181391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aspects of follicular and oocyte maturation that affect the developmental potential of embryos.","authors":"P. Mermillod, B. Oussaid, Y. Cognié","doi":"10.1530/BIOSCIPROCS.4.035","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.4.035","url":null,"abstract":"The ability to mature, be fertilized and finally to develop into a viable embryo is acquired gradually by the oocyte during progressive differentiation throughout folliculogenesis. This process starts with oocyte growth during the first steps of follicular development. As the oocyte is close to its final size, other modifications occur, less spectacular but at least as important in determining the resulting ability of the oocyte to accomplish its reproductive purpose (developmental competence). These modifications, referred to as 'oocyte capacitation', are probably influenced by the follicle. The proportion of developmentally competent oocytes increases with follicular size. However, the relationship between follicular growth and oocyte competence is not very strict, since a given oocyte may acquire its competence at any stage of follicular growth and since some examples of functional disjunction between follicular size and oocyte competence are described. Follicular atresia may impair the acquisition of oocyte competence, as evidenced by the parallel study of follicular characteristics and of the developmental potential of their oocytes treated individually through in vitro maturation, fertilization and development. However, when atresia is experimentally induced in large preovulatory follicles, oocytes remain competent, indicating that once competence is acquired, it is no longer sensitive to atresia. Oocyte maturation represents only the end of this long and progressive process and validates the preparation of the oocyte by conferring its final developmental ability. As evidenced by recent cloning experiments, the cytoplasmic aspects of oocyte maturation are crucial for the acquisition of developmental competence. This cytoplasmic maturation may be activated in vitro by the use of complex media supplement (serum, follicular fluid) but the use of defined media for maturation allowed the identification of some active factors (such as epidermal growth factor, growth hormone, inhibin and activin). The study of some differential models of oocyte competence (follicular size and atresia, Booroola gene, prepubertal oocytes) will provide a better understanding of oocyte capacitation and maturation, and allow the improvement of in vitro methods for oocyte maturation, which represent the most limiting step of in vitro production of embryos in large mammals.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"25 3 1","pages":"449-60"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79741308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maternal recognition of pregnancy.","authors":"W. Thatcher, M. Meyer, G. Danet-Desnoyers","doi":"10.1530/BIOSCIPROCS.3.002","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.3.002","url":null,"abstract":"Enhanced secretion of PGF2 alpha from endometrial explants in vitro in response to oxytocin is associated with augmented activities of phospholipase A2, phospholipase C and prostaglandin endoperoxide H synthase (PGS). In early pregnancy, maintenance of the corpus luteum is associated with an absence of pulsatile PGF2 alpha secretion; an increase in endometrial inhibitors of phospholipase A2 and PGS contribute to the antiluteolytic alterations of PGF2 alpha secretion. Linoleic acid is a competitive inhibitor of arachidonic acid metabolism by PGS, and microsomal concentrations of free linoleic acid are increased in the endometrium of pregnant cattle. The trophoblast produces large quantities of interferon tau (IFN-tau). Inhibition of increases in endometrial oestradiol receptor mRNA and protein are associated with intrauterine administration of recombinant (r) ovine (o) IFN-tau in sheep. Intrauterine injections of ovine (b) IFN-tau in cattle (days 14-17) altered endometrial function so that secretion of PGF2 alpha from cultured endometrial epithelial cells was reduced. Antiluteolytic effects were not expressed in 20% of cows receiving IFN-tau or rbIFN-alpha I1 indicating that an inadequate endometrial responsiveness may contribute to embryo mortality. IFN-tau may activate a signal transduction system similar to that induced by other type I IFNs; activation of an intracellular tyrosine kinase ultimately leads to activation of an IFN-stimulated response element to induce gene transcription. Biological responses associated with pregnancy and IFN-tau treatment are integrated into a multifactorial antiluteolytic model. Strategies to enhance embryo survival could include supplementation with rIFN-tau and alterations in endometrial responsiveness to this cytokine through dietary manipulation of lipid metabolism.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"367 1","pages":"15-28"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85472708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}