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See detailActivational and organizational disruption of folliculogenesis and estrous cycle caused by exposure to Bisphenol A (BPA) during early postnatal or adult life
Lopez Rodriguez, David ULg; Franssen, Delphine ULg; GERARD, Arlette ULg et al

Conference (2017, May 05)

Our previous studies have shown that an early postnatal exposure to a very low dose of bisphenol A (BPA) disrupts sexual maturation and pubertal timing. However, the long-term effects of such low dose ... [more ▼]

Our previous studies have shown that an early postnatal exposure to a very low dose of bisphenol A (BPA) disrupts sexual maturation and pubertal timing. However, the long-term effects of such low dose exposure as well as the effects of adult exposure have not been studied. One day-old and 90 day-old female rats received daily subcutaneous injections of corn oil (vehicle) or BPA (25ng/kg/d or 5mg/kg/d) for 15 days. The early postnatal exposure to both BPA doses significantly decreased the percentage of females with a regular cycle (BPA-25ng: 51±15%; BPA-5mg: 7±7%; OIL: 86±2%). The estrus cycle alterations were characterized by a decrease in time spent in proestrus (BPA-25ng: 13±3%; BPA-5mg: 12±3%; OIL: 18±3%). During adult exposure, both doses caused a disruption of the estrous cycle characterized by a significant decrease in the average time spent in proestrus (BPA-25ng: 19±2%; BPA-5mg: 17±1%; OIL: 23±1%). This effect was transient as the exposed females showed a regular cycle one month after the last dose of BPA. After adult exposure, we also observed a disruption of folliculogenesis characterized by a significant decrease of antral follicles (BPA-25ng: 21±2%; BPA-5mg: 21±2%; OIL: 36±2%) and increase of atretic follicles (BPA-25ng: 24±4%; BPA-5mg: 26±6%; OIL: 15±1%). GnRH secretion measured ex vivo 24h after adult exposure was moderately affected by BPA. Indeed, GnRH interpulse interval was significantly different when comparing animals exposed to the high or low dose of BPA but not when comparingexposed animals to the control group (BPA-25ng: 42.6±0.5; BPA-5mg: 40.2±0.6%; OIL: 41.1±0,2minutes±SEM). In conclusion, while exposure to BPA produces persistent alterations of the estrous cycle after early postnatal exposure, exposure during adulthood appears to cause activational non-persistent alternations of both the estrous cycle and folliculogenesis. [less ▲]

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See detailDelayed neuroendocrine sexual maturation in female rats after a very low dose of Bisphenol A through altered GABAergic neurotransmission and opposing effects of a high dose.
Franssen, Delphine ULg; GERARD, Arlette ULg; HENNUY, Benoit ULg et al

in Endocrinology (2016)

Rat sexual maturation is preceded by a reduction of the interpulse interval (IPI) of gonadotropinreleasing hormone (GnRH) neurosecretion. This work aims at studying disruption of that neuroendocrine event ... [more ▼]

Rat sexual maturation is preceded by a reduction of the interpulse interval (IPI) of gonadotropinreleasing hormone (GnRH) neurosecretion. This work aims at studying disruption of that neuroendocrine event in females after early exposure to a very low dose of Bisphenol A (BPA), a ubiquitous endocrine disrupting chemical. Female rats were exposed to vehicle or BPA 25 ng/kg.day, 25 g/kg.day, or 5 mg/kg.day from postnatal day (PND) 1 to 5 or 15. Exposure to 25 ng/kg.day of BPA for 5 or 15 days was followed by a delay in developmental reduction of GnRH IPI studied ex vivo on PND 20. After 15 days of exposure to that low dose of BPA, vaginal opening tended to be delayed. In contrast, exposure to BPA 5 mg/kg.day for 15 days resulted in a premature reduction inGnRHIPI and a trend toward early vaginal opening. RNAseq analysis on PND20 indicated that exposure to BPA resulted in opposing dose effectsonthemRNAexpression of hypothalamic genes involved inGABAA neurotransmission. The study of GnRH secretion in vitro in the presence of GABAA receptor agonist/antagonist confirmed an increased or a reduced GABAergic tone after in vivo exposure to the very low or the high dose of BPA, respectively. Overall, we show for the first time that neonatal exposure to BPA leads to opposing dose-dependent effects on the neuroendocrine control of puberty in the female rat. A very low and environmentally relevant dose of BPA delays neuroendocrine maturation related to puberty through increased inhibitory GABAergic neurotransmission. [less ▲]

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See detailThe effects of perinatal exposure to polychlorinated biphenyls on hippocampal neurogenesis
Pinson, Anneline ULg; Parent, Anne-Simone ULg; chatzi, christina et al

Poster (2015, May)

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See detailGene expression of growth factors and apoptosis regulating proteins in rat myocardium after exposure to endocrine disrupting chemicals : a preliminary study
ROUATBI, Hatem ULg; GERARD, Arlette ULg; Seghaye, Marie-Christine ULg

in Tijdschrift van de Belgische Kinderarts = Journal du Pédiatre Belge (2015, January), 17(1), 99

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See detailSexually dimorphic effect of gestational exposure to BPA on DNA methylation in the rat placenta
Fudvoye, Julie ULg; Dehan, Pierre ULg; Trooskens, G. et al

in Tijdschrift van de Belgische Kinderarts = Journal du Pédiatre Belge (2015, January), 17(1), 37

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See detailSexually dimorphic effect of gestational exposure to BPA on DNA methylation pattern in the rat placenta
FUDVOYE, Julie ULg; Dehan, Pierre ULg; Trooskens, Gheert et al

Conference (2014, October 27)

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