Changed control of cervical secretion from infertile ewes previously exposed to oestrogenic clover pasture

Adams, N. R.; Tang, B. Y.

doi:10.1530/jrf.0.0760147

Cited by 7 publications

(5 citation statements)

References 16 publications

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“…In ovariectomized ewes, the production of mucus is limited and consists primarily of sulfomucins. The production of mucins is under endocrine control as supplementation with oestradiol benzoate increases the production of mucus, increases the water content and restores the production of sialomucins (Adams and Tang 1979, 1986). The secretions of the cervix are subject to morphological and biochemical changes during the oestrous cycle, as the amount of mucus and its degree of hydration increase considerably during oestrus (Katz et al.…”

Section: Secretions Of the Cervixmentioning

confidence: 99%

Sperm Interaction with the Female Reproductive Tract

Druart¹

2012

Reprod Domestic Animals

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Contents Sperm transit in the female tract is a critical event for the success of fertilization. From their deposition in the vagina to final migration in the oviduct, sperm pass through the different compartments of the genital tract in which they encounter different environments. The cervix and the uterotubal junction (UTJ) are two barriers with different relative importance according to the species. The protein composition, the degree of glycosylation and the hydration of the cervical mucus change during the oestrous cycle. Several sperm surface proteins are associated with their migration through the cervical mucus and the UTJ. Data regarding the interaction of sperm with secretions of the epithelial tissue lining the different compartments of the female genital tract during the sperm transit are reviewed, with a particular emphasis on the migration of sperm through the cervix.

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Section: Secretions Of the Cervixmentioning

confidence: 99%

Sperm Interaction with the Female Reproductive Tract

Druart¹

2012

Reprod Domestic Animals

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“…In most mammalian species, the genes for oestrogen-directed morphogenesis are switched off after the completion of organogénesis. However, in the ewe they may be re-activated to a slight extent during adult life by plant oestrogens (Adams & Martin, 1983;Adams & Tang, 1986), thereby producing permanent infertility. This has normally been considered a pathological process, but the demonstration that similar changes can be produced by oestradiol-17ß, an endogenous steroid, suggests that some of these effects may be expressed during normal physiological processes.…”

Section: Discussionmentioning

confidence: 99%

“…The cervical malfunction is associated with a reduced spinnbarkeit (capacity to be drawn into threads) in the cervical mucus (Adams, 1976) and a change in the histological structure so that the cervical archi¬ tecture and cells appear more like endometrium (Heydon & Adams, 1977). These changes occur as part of a general sexual transdifferentiation in affected ewes (Adams & Tang, 1986), and are accompanied by slight defeminization and masculinization of sexual behaviour (Adams, 1983) and an impairment of the sex-dependent mechanism controlling the preovulatory surge of LH (Adams Such sexual transdifferentiation is most unusual in adult mammals, and the question arises as to whether it is an aberrant response to oestrogenic isoflavones, or whether it can also be produced by a more physiological oestrogen such as oestradiol-17ß. In the present study, therefore, adult ewes were exposed to oestradiol-17ß for a prolonged period and examined for the functional abnormalities which have been reported in ewes with clover disease.…”

Section: Introductionmentioning

confidence: 99%

Persistent infertility in ewes after prolonged exposure to oestradio-17

Adams

Sanders²

1988

Reproduction

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Merino ewes were treated with implants which released 300 micrograms oestradiol-17 beta per day or 5 mg progesterone per day, or both, for 9 months (Months 1-9), and after an 11-month intermission were treated again for 6 months (Months 20-26). Ewes were run with rams at Months 16, 28 and 40. Fertility was not affected by the first exposure period, but the second exposure to oestradiol reduced the fertility of ewes at both subsequent mating periods. Affected ewes returned to service more frequently (P less than 0.01) and were less likely to conceive (P less than 0.05). After mating, a normal population of spermatozoa was established in the caudal cervix, but transport through the cervix was impaired in affected ewes and there were fewer spermatozoa (P less than 0.01) in the cranial cervix. In affected ewes, the spinnbarkeit of cervical mucus was reduced (P less than 0.05), and the histological appearance of the cervix changed, looking like that of the uterus. Treatment with progesterone did not affect fertility, cervical mucus or sperm transport, but diminished the histological abnormalities produced by oestradiol (P less than 0.05). These results show that oestradiol-17 beta given after puberty can cause the same kind of permanent sexual transdifferentiation that is produced by the oestrogenic isoflavones in ewes with clover disease. The results suggest that this change may require more than a single exposure to oestrogen.

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“…The spinnbarkeit, which is the length to which a strand of mucus can be drawn out before it breaks, is a measure of the viscoelasticity of the mucus. In in-fertile ewes, cervical mucus is watery and easily penetrable, but the spinnbarkeit of cervical mucus is reduced (9). The low viscoelasticity results in the loss of spermatozoa from the cervix, presumably through the vagina, so fewer sperm reach the oviduct and the chance of conception is reduced.…”

Section: Organizational Effectsmentioning

confidence: 99%

Organizational and Activational Effects of Phytoestrogens on the Reproductive Tract of the Ewe

Adams

1995

Experimental Biology and Medicine

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Ewes exposed to phytoestrogens may display two forms of infertility, categorized as temporary or permanent. Temporary infertility results from actions of estrogen that are similar to the activational effects of estrogen in most species of mammals. The permanent infertility results from changes to the cervix which are analogous to the organizational effects of estrogen reported in other species treated during organogenesis. However, in the ewe these effects may be produced after organogenesis by prolonged treatment during adult life. It has recently become apparent that the level of nutrition and metabolic hormones influence the degree of uterus-like histological change in the cervix produced by prolonged treatment with estrogen. It is hypothesized that, under some nutritional conditions, the hormonal milieu in adult ewes may simulate hormonal patterns that are normally experienced by fetal lambs in utero, thereby allowing the cervix of the adult ewe to give an organizational response to estrogen.

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Changed control of cervical secretion from infertile ewes previously exposed to oestrogenic clover pasture

Cited by 7 publications

References 16 publications

Sperm Interaction with the Female Reproductive Tract

Sperm Interaction with the Female Reproductive Tract

Persistent infertility in ewes after prolonged exposure to oestradio-17

Organizational and Activational Effects of Phytoestrogens on the Reproductive Tract of the Ewe

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