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| RECABARREN,SERGIO E; LOBOS,ALEJANDRO; TORRES,VERÓNICA; OYARZO,ROBERTO; SIR-PETERMANN,TERESA. |
| Leptin, the product of the ob gene, has been proposed as a metabolic signal that regulates the secretion of GnRH/LH. This may be critical during prepubertal development to synchronize information about energy stores and the secretion of GnRH/LH. This study aimed to assess the effect of food restriction on the episodic secretion of leptin and LH in young female sheep. Five 20-week-old prepubertal females were fed a low-level diet for 10 weeks to maintain the body weight. Control females of the same age received food ad libitum. Blood samples were collected at 10-min intervals for six hours at 20, 26, and 30 weeks of age, and plasma leptin, LH, insulin and cortisol concentrations were measured. In the control group, no changes were found in pulsatile LH... |
| Tipo: Journal article |
Palavras-chave: Female sheep; Food restriction; Leptin; LH; Puberty. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000300003 |
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| RECABARREN,SERGIO E; LOBOS,ALEJANDRO; FIGUEROA,YARA; PADMANABHAN,VASANTHA; FOSTER,DOUGLAS L; SIR-PETERMANN,TERESA. |
| Although evidence is accumulating that prenatal testosterone (T) compromises reproductive function in the female, the effects of excess T in utero on the postnatal development of male reproductive function has not been studied. The aim of this study was to assess the influence of prenatal T excess on age-related changes in pituitary and gonadal responsiveness to GnRH in the male sheep. We used the GnRH agonist, leuprolide (10 µg/kg), as a pharmacologic challenge at 5, 10, 20 and 30 weeks of age. These time points correspond to early and late juvenile periods and the prepubertal and postpubertal periods of sexual development, respectively. LH and T were measured in blood samples collected before and after GnRH agonist administration. The area under the... |
| Tipo: Journal article |
Palavras-chave: Fetal programming; IUGR; Pituitary sensitivity. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602007000400007 |
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| RECABARREN,SERGIO E; SIR-PETERMANN,TERESA; LOBOS,ALEJANDRO; CODNER,ETHEL; ROJAS-GARCÍA,PEDRO P; REYES,VÍCTOR. |
| Similar to women with Polycystic Ovary Syndrome (PCOS), female sheep treated prenatally with testosterone (T-females) are hypergonadotropic, exhibit neuroendocrine defects, multifollicular ovarian morphology, hyperinsulinemia and cycle defects. Hypergonadotropism and multifollicular morphology may in part be due to developmentally regulated increase in pituitary responsiveness to GnRH and may culminate in increased ovarian estradiol production. In this study, we utilized a GnRH agonist, leuprolide, to determine the developmental impact of prenatal testosterone exposure on pituitary-gonadal function and to establish if prenatal exposure produces changes in the reproductive axis similar to those described for women with PCOS. Eight control and eight... |
| Tipo: Journal article |
Palavras-chave: Androgenized females; Fetal programming; PCOS; Leuprolide; Female sheep. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000200013 |
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