The Ontogeny of Fetal Adrenal Steroidogenesis as a Prerequisite for the Initiation of Parturition

Conley, Alan J; Neto, Antônio Chaves de Assis

doi:10.1055/s-2008-1076713

Cited by 13 publications

(11 citation statements)

References 80 publications

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“…In contrast, the increase in fetal cortisol is initiated much earlier in livestock species, beginning from a few days to a few weeks before term [161]. Administration of ACTH to equine fetuses after 300 days of gestation induces both fetal maturation and early delivery [162].…”

Section: The Initiation Of Parturitionmentioning

confidence: 92%

Review of the reproductive endocrinology of the pregnant and parturient mare

Conley

2016

Theriogenology

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Section: The Initiation Of Parturitionmentioning

confidence: 92%

Review of the reproductive endocrinology of the pregnant and parturient mare

Conley

2016

Theriogenology

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“…Studies about cytochrome P450 enzymes in adrenal glands have been useful for other researches reporting the relationship of adrenal hormones with several diseases (Hîncu et al, 2006;Kempná and Fluck, 2008;Miller, 2009;Laborie et al, 2011;Parker et al, 2011), genetic disorders (Mapes et al, 1999) and its relationship with the mechanisms of birth in several mammals (Conley and Assis-Neto, 2008;Miller, 2009). Studies related to the hypothalamic-pituitary-adrenal (Parker et al, 2011), androgenization of mammals female due the large production of androgen hormones by the adrenal (Yalcinkaya et al, 1993;Ostner et al, 2003) and adrenal changes related to photoperiod were also found (Ribes et al, 1999;Schibler and Brown, 2005).…”

Section: Introductionmentioning

confidence: 99%

Adrenal glands of Spix's yellow-toothed cavy (Galea spixii, Wagler, 1831): morphological and morphometric aspects

et al. 2016

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Considering the physiological importance and need of greater morphophysiological knowledge of adrenal glands, the aims of present study were compare the morphometric data between left and right adrenal of male and female; perform a histological, scanning and transmission electron microscopy study showing tissue constitution of glands; finally, in order to define the presence and correct site of the cytochrome P450c17 expression in adrenal glands, immunohistochemical study of this enzyme was performed in 18 adrenal glands (right n=9 and left n=9) of nine adult Galea spixii (four males and five females). Right adrenal was more cranially positioned than left adrenal; dimensions (weight, length and width) of right adrenal was larger than left adrenal; no differences between male and female body and adrenal measurements were found; the morphology of cells and different amounts of lipid droplets may be related to the different demands of steroid hormones production, related to each zone of the adrenal cortex; and, the cytochrome P450c17 immunolocalization in fasciculate and reticular zone may be related with synthesis of 17-hydroxy-pregnenolone, 17-hydroxy-progesterone, dehydroepiandrosterone or androstenedione.Keywords: adrenal cortex, adrenal medulla, CYP, steroidogenic enzymes, wild rodents. Glândulas adrenais de preás (Galea spixii, Wagler, 1831):aspectos morfológicos e morfométricos ResumoConsiderando a importância fisiológica e a necessidade de melhor conhecimento morfofisiológico das glândulas adrenais, os objetivos do presente estudo foram comparar dados morfométricos entre adrenais direitas e esquerdas de machos e fêmeas; realizar estudos histológicos e microscopia eletrônica de varredura e transmissão revelando a constituição tecidual das glândulas; finalmente, foi realizado estudo imunohistoquímico com objetivo de definir a presença e correto sítio de expressão da citocromo P450c17 nas glândulas adrenais em 18 glândulas adrenais (direita n=9 e esquerda n=9) de nove Galea spixii adultos (quatro machos e cinco fêmeas). A glândula adrenal direita estava posicionada mais cranialmente que a adrenal esquerda; as dimensões (peso, comprimento e largura) da glândula adrenal direita foram maiores que as da esquerda; não houve diferença entre as medidas corpóreas e das adrenais entre machos e fêmeas; a morfologia das células e diferentes quantidades de gotículas lipídicas podem estar relacionadas a diferentes demandas na produção de hormônios esteroides relacionados a cada zona do córtex adrenal; e, a imunolocalização da citocromo P450 na zona fasciculada e reticular pode estar relacionado com a síntese de 17-hidroxi-pregnenolona, 17-hidroxi-progesterona, dehidroepiandrosterona ou androstenediona.Palavras-chave: córtex adrenal, medula adrenal, CYP17, enzimas esteroidogênicas, roedores silvestres.

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“…There are two times during gestation when P450c17 and P450arom activities increase significantly. The first time is at mid-gestation, when the increase in the expression of P450c17 (Conley et al, 1992) accompanies an early rise in foetal cortisol as a result of early foetal adrenal activation (Lund et al, 1988;Conley and Assis Neto, 2008). The activity of P450arom also increases significantly at about the fifth month of gestation and drops abruptly afterward (Tsumagari et al, 1993).…”

Section: Changes In Steroidogenic Activity Throughout Pregnancymentioning

confidence: 99%

“…The increase in maternal, peripheral oestrogen concentrations from midgestation through parturition is, in part, because of the increase in the size of the placenta. The sharp rise in oestrogen synthesis at mid-gestation is associated with an increase in the expression of placental cytochrome P450 17a-hydroxylase/17,20-lyase (P450c17; Conley et al, 1992), a key enzyme in oestrogen synthesis, that accompanies the early activation of the foetal adrenal glands (Conley and Assis Neto, 2008). Similarly, the increase in oestrogen synthesis just before parturition is caused by the pre-partum induction of placental P450c17 activity by foetal cortisol produced by the adrenal glands as a consequence of the maturation of the foetal pituitaryadrenal-axis (Conley et al, 1992;Schuler et al, 1994).…”

Section: Oestrogen Productionmentioning

confidence: 99%

“…Steroid hormones, when present in the proper concentrations and ratios to one another, are critical for the progression of pregnancy, normal foetal development and for signalling the timing of parturition (King, 1993;Conley and Assis Neto, 2008). During pregnancy, progesterone inhibits the ovulatory surges of luteinizing hormone (LH), prepares the endometrium for implantation, and maintains myometrial quiescence while stimulating the production of a variety of endometrial secretions that support the successful development of the embryo (Geisert et al, 1992;Lye, 1996;Goff, 2004).…”

Section: Introductionmentioning

confidence: 99%

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Multilevel regulation of steroid synthesis and metabolism in the bovine placenta

Nguyen

Conley

Soboleva

et al. 2012

Molecular Reproduction Devel

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SUMMARYSteroid hormones play critical roles in almost all physiological processes in male and female reproduction. In a normal pregnancy, the concentrations of steroid hormones in maternal and foetal blood vary with gestation in response to changing needs. The placenta plays a central role in producing the appropriate steroids to support the pregnancy by coordinating its own steroidogenic activity with that of the corpus luteum and responding to foetal signals. Although much is known about the steroidogenic potential of the bovine placenta, far less is known about how the placenta integrates the synthesis of steroids with their subsequent metabolism and clearance to achieve appropriate local and peripheral concentrations of steroids in maternal and foetal blood at each stage of gestation. This review focuses on the current knowledge of the temporal and spatial regulation and compartmentalization of the biochemical pathways by which potent steroid hormones are synthesized and metabolized in the bovine placenta. The aim is to increase our understanding of how the balance of synthesis and metabolism determines placental steroid output as it changes with development and differentiation, and how this is regulated in response to the variations in the foetal signals and luteal secretory activity. The review highlights knowledge gaps and suggests that mathematical modelling can help understand the effect of different levels of regulation on the steroidogenic output of an organ, such as the bovine placenta.

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The Ontogeny of Fetal Adrenal Steroidogenesis as a Prerequisite for the Initiation of Parturition

Cited by 13 publications

References 80 publications

Review of the reproductive endocrinology of the pregnant and parturient mare

Review of the reproductive endocrinology of the pregnant and parturient mare

Adrenal glands of Spix's yellow-toothed cavy (Galea spixii, Wagler, 1831): morphological and morphometric aspects

Multilevel regulation of steroid synthesis and metabolism in the bovine placenta

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