Biological activity of the seminal plasma of alpacas: stimulus for the production of LH by pituitary cells

Paolicchi, Fernando Alberto; Urquieta, Bessie; Valle, Luís J. del; Bustos‐Obregón, Eduardo

doi:10.1016/s0378-4320(98)00150-x

Cited by 41 publications

(36 citation statements)

References 11 publications

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“…Treatment with OIF and GnRH induced more LH secretion than untreated controls, and LH concentrations were greater in wells treated with higher doses of OIF or GnRH compared to wells treated with alower dose. This is in agreement with the dose-depending effect of OIF observed in vivo (Tanco et al, 2011), and a previous study in which alpaca SP stimulated LH secretion from rat anterior pituitary cells in vitro (Paolicchi et al,1999). Although these results do not keep out a possible effect of hypothalamus level, they confirmed that OIF has a direct effect on pituitary gonadotrophs independent of hypothalamic input GnRH (Silva et al, 2011).…”

Section: Advances In Animal and Veterinary Sciencessupporting

confidence: 92%

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Overview of New Concepts in Induce Ovulation Triggers in Dromedary Camels

Al-Fatlawy¹,

Baiee²

2018

Adv. Anim. Vet. Sci.

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IntroductIonH ypothalamuses canpulsatile release the GnRH into the hypophyseal portal system with subsequent release of LH from the anterior pituitary into systemic circulation for inducing ovulation in mammals. The broad classification of species as either spontaneous or induced ovulators is based on the type of stimulus responsible for eliciting GnRH release from the hypothalamus (Adam et al., 2005). In spontaneously ovulating species (such as human, sheep, cattle, horse and pigs), the releasing of GnRH from the hypothalamus is triggered in the absence of progesterone and systemic estradiol concentrations exceed a threshold. In the induced ovulators (such as rabbits, ferrets, cats and camelids) the releasing of GnRH is contingent upon copulatory stimuli; hence, the ovulation is not a regular cyclic event (Bakker and Baum, 2000; Adam et al., 2005). Since a classic 1970 Peruvian study, dogma has maintained that physical stimulation of the genitalia during copulation is the primary trigger for inducing ovulation in alpacas and llamas. It is inaccurate to apply the term "oestrous cycle" in camels due to the pattern of ovulation in these animals,in contrast in spontaneous ovulators such as the cow and the mare (Bravo et al., 1990;Bravo et al., 1991).Camels are seasonally polyestrous animals with estrous cycle differed from that in other farm animals. The estrous cycle in camel is characterized by three phases lasting 24-28 days with absence of the luteal phase. These phases are including follicular growth, existence of mature follicles (estrous period) and follicular atresia. The estrous period is longer up to 8 days (Shalash, 1980;Shalash, 1987;Skidmore et al., 1996;Skidmore et al., 2009).Ovulation in the camel as in cat and rabbit occurs normally after the coitus. In these animals the neuroendocrine reflex involving the initiation of luteinising hormone release is delayed until coitus occurs . Manual stimulation of the cervix for 15 minutes in the camel did not induce ovulation but cause only partial luteinisation of the Graafian follicle, ovulation occurs 32 to 40 hours after copulation under the influence of luteinising hormone (LH) (Musa & Abu Sineina, 1978b;Wilson, 1984;Yagil, 1985). OvulatiOn induced FactOr (OiF): discOvery research ArticleAbstract | The seminal plasma consists of several components that stimulate the ovulation process. The great quantity of an ovulation-inducing factor (OIF) in seminal plasma has wide implication questions about identification, sources, mechanism of action, role among species and clinical applications in the infertility. The purpose of the current review is to focus on the current understanding of physiological and biochemical properties of seminal plasma in camelids. llamas and alpaca seminal plasma was used as agent of induced and spontaneous ovulators. Column chromatography was used to identify the ovulation-inducing factor as part of seminal plasma that stimulating hormone secretion (LH) and ovulation in llamas. OIF is β-NGF that is highly conserved. An endocrine rout...

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Section: Advances In Animal and Veterinary Sciencessupporting

confidence: 92%

“…It is also acted as a potent stimulator of LH secretion, and has a dose-dependent effect on ovulation rate and CL form and function. Moreover, it acts via a systemic rather than a local pathway, at physiologically relevant doses Chen et al, 1985;Sokol et al, 1985;Izumi et al, 1985;Paolicchi et al 1999).…”

Section: Advances In Animal and Veterinary Sciencesmentioning

confidence: 99%

Overview of New Concepts in Induce Ovulation Triggers in Dromedary Camels

Al-Fatlawy¹,

Baiee²

2018

Adv. Anim. Vet. Sci.

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“…Several lines of evidence support the proposal that the effects of SP may extend to affect ovarian function. Seminal components are involved in the mechanism of coitus-induced ovulation in Camelid species (Chen 1985, Paolicchi 1999, Pan et al 2001, koalas (Johnston et al 2004) and in pigs, a SP-induced uterine intermediate has been implicated at the time of ovulation (Waberski et al 1997a(Waberski et al ,b, 1999. While the mechanisms underlying these ovarian effects are not completely understood, it is reasonable to suggest a contribution due to local inflammatory mediators in ovarian responses.…”

Section: Introductionmentioning

confidence: 99%

Seminal plasma regulates ovarian progesterone production, leukocyte recruitment and follicular cell responses in the pig

O’Leary

Jasper²,

Robertson³

et al. 2006

Reproduction

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Seminal plasma (SP) acts to influence the uterine endometrium after mating, activating synthesis of embryotrophic cytokines and inflammatory changes that condition the tract for embryo implantation and establishing pregnancy. The objective of this study was to investigate in pigs whether the ovary might also be responsive to SP exposure. Prepubertal gilts were synchronised with exogenous gonadotrophins and received transcervical treatment with pooled boar SP or PBS; then the ovarian tissue was recovered at 34 h (preovulation) and on days 5 and 9 after treatment. The ovarian response was assessed by measuring ovulation rate, number and size of corpora lutea, ovarian leukocyte populations, progesterone production in vivo, as well as responses of retrieved granulosa cells cultured in vitro. In SP-treated gilts, leukocyte recruitment into the ovarian tissues was increased fourfold at 34 h, with macrophages comprising the most abundant cell lineage. There was no effect of SP on the number of oocytes ovulated; however, the weight of corpora lutea was increased in SP-treated gilts. SP also induced an increase in plasma progesterone content seen from day 5 to at least day 9 after treatment. In addition, granulosa cells and thecal tissue retrieved from preovulatory follicles of SP-treated gilts were more responsive in vitro to growth factor-and gonadotrophin-stimulated cell proliferation and progesterone synthesis. These results suggest that uterine exposure to SP influences immune cell trafficking in the ovary and enhances steroidogenesis in early pregnancy. The effects of SP on ovarian function potentially contribute to reproductive success in the pig.

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“…All of this confirms that ovulation in camelid species is provoked by semenderived chemical signals via neuroendocrine pathways (Berland et al, 2016). However, the exact route of action of the β-NGF on LH secretion is not clear; suggesting an action in the hypothalamus level would stimulate the GnRH secretion (Silva et al, 2011) or a direct effect on the anterior pituitary causing the release of LH (Paolicchi et al, 1999;Bogle et al, 2012).…”

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confidence: 60%