Sex-hormone binding globulin from sheep serum: purification and effects of pregnancy and treatment with exogenous estradiol

Kouretas, Demetrios; Laliotis, V.; Taitzoglou, Ioannis; Georgellis, Antonis; Tsantarliotou, Maria; Mougios, Vassilis; Amiridis, G.S.; Antonoglou, O.

doi:10.1016/s0742-8413(99)00028-6

Cited by 6 publications

(4 citation statements)

References 23 publications

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“…In this species, compared to others, circulating estradiol is very low, normally ranging from less than 1 pg/ml during the mid-luteal phase to approximately 10 pg/ml 2-3 days prior to the pre-ovulatory LH surge [19]. Low estradiol levels are more potent in sheep than in other species due to the low binding affinity of sex hormone-binding globulin (SHBG) for estradiol in this species [20,21].…”

Section: Introductionmentioning

confidence: 82%

Long-Term Exposure of Female Sheep to Physiologic Concentrations of Estradiol: Effects on the Onset and Maintenance of Reproductive Function, Pregnancy, and Social Development in Female Offspring1

Malcolm

Jackson

Bergeon

et al. 2006

Biology of Reproduction

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As steroids and steroid-like compounds accumulate in the environment, it has become important to understand how low-dose exposure affects reproductive function. Ovary-intact sheep were used in a multigenerational study, to determine whether chronic exposure to low levels of estrogen disrupts reproductive function and behavior. We assessed parameters of reproductive performance in control and postnatally estradiol-treated females (Generation 1, G1), and their offspring (Generation 2, G2). In the G1 animals, 17beta-estradiol (E) was administered continuously from 4 wk of age at two doses via subcutaneous implants (ultralow E [<1 pg/ml in circulation, n = 8] or low E [1-3 pg/ml, n = 8]). Both doses delayed puberty; low E also produced pronounced prepubertal and seasonal anestrus hypogonadotropism, and delayed the onset of the second breeding season. All G1 animals conceived and produced offspring (G2), the treatment of which resulted from continuous maternal exposure during pregnancy and lactation. Behavioral observations of G2 females revealed that low prenatal E modestly masculinized play behavior and increased the frequency of attempts to displace competitors relative to ultralow E and control animals. The timing and magnitude of the LH surge also differed in prepubertal low prenatal E females relative to the controls, although these differences were not evident when retested at one year of age. These findings support the hypothesis that chronic exposure to physiologic amounts of exogenous estrogens has multigenerational effects on behavior and neuroendocrine function. Despite these disruptive steroid actions, ovarian cyclicity and fertility are not invariably compromised, pointing to an impressive resiliency of the reproductive axis to insult by exogenous estrogenic compounds.

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Section: Introductionmentioning

confidence: 82%

Long-Term Exposure of Female Sheep to Physiologic Concentrations of Estradiol: Effects on the Onset and Maintenance of Reproductive Function, Pregnancy, and Social Development in Female Offspring1

Malcolm

Jackson

Bergeon

et al. 2006

Biology of Reproduction

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“…In contrast to oestrogen administered via the systemic circulation, oral oestrogens are delivered to the liver once absorbed and thus have an increased ability to affect SHBG synthesis directly [25]. Both oral and intramuscular oestrogen administrations have been reported to have no effect on SHBG levels in sheep [26] suggesting that species specific effects should not be excluded.…”

Section: Discussionmentioning

confidence: 99%

Biosensor-based detection of reduced sex hormone-binding globulin binding capacities in response to growth-promoter administrations

Mooney¹,

Bergwerff

Meeuwen

et al. 2009

Analytica Chimica Acta

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“…Why plasma SHBG increases so much during pregnancy in some species but not others is not fully understood, but it may be related to species differences in the magnitude of estrogen production by the placenta and/or its subsequent effects on hepatic Shbg expression. In support of this, maternal sheep plasma SHBG levels do not change during pregnancy and are not increased by exogenous estrogen treatment [45]. In species for which plasma SHBG increases during pregnancy, it has been thought that this protects the fetus from exposures to maternal sex steroids, but the opposite actually might be closer to reality.…”

Section: During Fetal Developmentmentioning

confidence: 91%

Diverse Roles for Sex Hormone-Binding Globulin in Reproduction

Hammond

2011

Biology of Reproduction

262

179

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Sex hormone-binding globulin (SHBG) transports androgens and estrogens in blood and regulates their access to target tissues. Hepatic production of SHBG fluctuates throughout the life cycle and is influenced primarily by metabolic and hormonal factors. Genetic differences also contribute to interindividual variations in plasma SHBG levels. In addition to controlling the plasma distribution, metabolic clearance, and bioavailability of sex steroids, SHBG accumulates in the extravascular compartments of some tissues and in the cytoplasm of specific epithelial cells, where it exerts novel effects on androgen and estrogen action. In mammals, the gene-encoding SHBG is expressed primarily in the liver but also at low levels in other tissues, including the testis. In subprimate species, Shbg expression in Sertoli cells is under the control of follicle-stimulating hormone and produces the androgen-binding protein that influences androgen actions in the seminiferous tubules and epididymis. In humans, the SHBG gene is not expressed in Sertoli cells, but its expression in germ cells produces an SHBG isoform that accumulates in the acrosome. In fish, Shbg is produced by the liver but has a unique function in the gill as a portal for natural steroids and xenobiotics, including synthetic steroids. However, salmon have retained a second, poorly conserved Shbg gene that is expressed only in ovary, muscle, and gill and that likely exerts specialized functions in these tissues. The present review compares the production and functions of SHBG in different species and its diverse effects on reproduction.

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Sex-hormone binding globulin from sheep serum: purification and effects of pregnancy and treatment with exogenous estradiol

Cited by 6 publications

References 23 publications

Long-Term Exposure of Female Sheep to Physiologic Concentrations of Estradiol: Effects on the Onset and Maintenance of Reproductive Function, Pregnancy, and Social Development in Female Offspring1

Long-Term Exposure of Female Sheep to Physiologic Concentrations of Estradiol: Effects on the Onset and Maintenance of Reproductive Function, Pregnancy, and Social Development in Female Offspring1

Biosensor-based detection of reduced sex hormone-binding globulin binding capacities in response to growth-promoter administrations

Diverse Roles for Sex Hormone-Binding Globulin in Reproduction

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