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Publications (3)5.37 Total impact

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    ABSTRACT: The kisspeptin (Kp) signaling pathway plays an essential role in the onset of reproduction in mammals. To investigate the effects of Kp on the initiation of egg laying in birds, juvenile female quail were given daily intraperitoneal injections of 300μl saline (control, Con), or 10nmol (low dosage, L) or 100nmol (high dosage, H) kisspeptin-10 (Kp-10) dissolved in 300μl saline for 3 weeks. The ratio of egg laying of quail in the L and H groups was notably increased compared to that of the Con group (P<0.01), which paralleled earlier ovarian growth and increases in circulating estrogen (E(2)) concentrations. In the hypothalamus, gonadotropin-releasing hormone-I (GnRH-I) mRNA expression was markedly up-regulated, whereas the level of gonadotropin-inhibiting hormone mRNA was down-regulated by high-dose Kp-10 (P<0.05). In the pituitary gland, expression of GnRH receptor type II, but not type I mRNA was significantly up-regulated by high-dose Kp-10 administration (P<0.05). Moreover, compared with the Con group, follicle-stimulating hormone (FSH) gene expression in the pituitary was significantly decreased in the L and H groups (P<0.05), whereas luteinizing hormone (LH) mRNA expression was significantly increased in the H, but not the L group (P<0.05). These results indicate that repeated peripheral Kp-10 injections can advance the sexual maturation of female quail by regulating the activities of the hypothalamus-pituitary-gonadal axis.
    Animal reproduction science 08/2012; 134(3-4):203-9. · 1.56 Impact Factor
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    ABSTRACT: Previous studies have shown that the in ovo injection of equol can markedly improve the water-holding capacity of muscles of broilers chickens at 7 wk of age through promotion of the antioxidant status. We aimed to investigate directly the antioxidant effects of equol on muscle cells in broilers. Muscle cells were separated from leg muscle of embryos on the 11th day of incubation and treated with equol and H(2)O(2), either alone or together. Cells were pretreated with medium containing 1, 10, or 100 μM equol for 1 h prior to the addition of 1 mM H(2)O(2) for a further 1 h. Photomicrographs of cells were obtained. Cell viability, malondialdehyde (MDA) content, and L-lactate dehydrogenase (LDH) activity in the cell supernatant, as well as intracellular total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activities were determined. Treatment with 1 mM H(2)O(2) caused serious damage to cells, indicated by comets with no clear head region but a very apparent tail of DNA fragments. Pretreatment with low (1 μM) but not high concentrations of equol (10 μM) inhibited cell damage, while 100 μM equol caused more serious damage than H(2)O(2) alone. Pretreatment with 1 μM equol had no effect on cell viability, while pretreatment with 10 and 100 μM equol significantly decreased cell viability in a dose-dependent manner. Compared with H(2)O(2) alone, pretreatment with low-dosage equol markedly decreased LDH activity and MDA production in the supernatant, significantly increased intracellular T-SOD activity (P < 0.05) and tended to increase intracellular GSH-Px activity (0.05 < P < 0.1). Pretreatment with high-dosage equol (10 and 100 μM) significantly enhanced LDH activity, but had no effect on MDA content, T-SOD or GSH-Px activity induced by H(2)O(2,) except for an obvious increase in GSH-Px activity caused by 10 μM equol. These results indicate that equol at low dosage can prevent skeletal muscle cell damage induced by H(2)O(2), while pretreatment with high-dosage equol shows a synergistic effect with H(2)O(2) in inducing cell damage.
    In Vitro Cellular & Developmental Biology - Animal 11/2011; 47(10):735-41. · 1.29 Impact Factor
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    ABSTRACT: The effect of kisspeptin-10 (Kp-10) on the secretion of progesterone (P(4)) was investigated in cultured granulosa cells from F(1) to F(3) follicles of hens. The results showed that granulosa cells were stained with clear signals for kisspeptin using immunocytochemistry with the specific antibody against Kp-10. Among 10, 100 and 1000 nM concentrations tested, 100 nM Kp-10 treated for 24h significantly increased P(4) secretion in granulosa cells from F(1) to F(3) follicles. After 24h and 48 h of treatment, 100 nM Kp-10 showed a significant increase in P(4) secretion, while after 72 h of treatment P(4) secretion was markedly decreased by Kp-10 compared to the control group (P<0.05). F(1) and F(2/3) cells treated with 100 nM Kp-10 for 24h showed significantly increased viability (P<0.05) and which was in parallel to a marked increase in P(4) secretion (P<0.01). Real-time PCR results showed that the gene expression of the steroidogenic acute regulatory protein (StAR), cytochrome P450 side-chain cleavage (P450scc) and the enzyme 3β-hydroxysteroid dehydrogenase (3β-HSD) in F(1) and F(2/3) granulosa cells was significantly up-regulated by 24h-100 nM Kp-10 treatment (P<0.05 versus P<0.01, respectively). However, there was no significant difference in StAR, P450scc and 3β-HSD protein content between control and the Kp-10 treated group (P>0.05). These results indicate that Kp-10 stimulates P(4) secretion in cultured chicken granulosa cells, which was associated with an up-regulation in StAR, P450scc and 3β-HSD gene transcription.
    Peptides 09/2011; 32(10):2091-7. · 2.52 Impact Factor