Leptin enhances ovulation and attenuates the effects produced by food restriction

Roman, Erika; Ricci, Analía Gabriela; Faletti, A.

doi:10.1016/j.mce.2005.07.007

Cited by 32 publications

(30 citation statements)

References 46 publications

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“…In previous studies, we found that ovulation is significantly inhibited by an acute treatment with leptin (Ricci et al 2006). However, we have also observed that a chronic treatment with a low dose of this protein enhances the ovulatory process in comparison with control animals and partially prevents the negative effects produced by a severe malnutrition (Roman et al 2005).…”

Section: Introductionmentioning

confidence: 59%

“…However, most of these studies are contradictory, since both stimulatory and inhibitory actions on the ovarian function have been described (Ahima et al 1997, Zachow & Magoffin 1997, Clément et al 1998, Strobel et al 1998, Agarwal et al 1999, Barkan et al 1999, Brannian et al 1999, Zachow et al 1999, Duggal et al 2000, 2002a, Almog et al 2001. Recently, we have demonstrated that leptin may be regulating the ovulatory process, as when the levels of this protein are low there is a positive relationship between leptin and the ovarian function (Roman et al 2005), while when these levels are high, there is a negative relationship between them (Ricci et al 2006). In this work, we studied the expression of leptin receptors in the rat HPO axis during the ovulatory process and found that gonadotropins regulate these receptors in a differential way.…”

Section: Discussionmentioning

confidence: 97%

“…In previous studies, using immature rats primed with eCG/hCG, we found that an acute treatment with leptin inhibits the ovulatory process (Ricci et al 2006), whereas a chronic administration with a low dose of this protein enhances it (Roman et al 2005). Therefore, we investigated whether these treatments were able to modify the expression of leptin receptors.…”

Section: Ctrlmentioning

confidence: 96%

“…injections of either recombinant rat leptin (5 mg/0 . 15 ml PBS-BSA) or PBS-BSA alone (control) 1 h before hCG administration and at intervals of 150 min until killing and 2) chronic treatment (Roman et al 2005), at 22 days of age, in which the rats received an i.p. injection of either recombinant rat leptin (3 mg/0 .…”

Section: In Vivo Studiesmentioning

confidence: 99%

“…Progesterone and 17b-oestradiol were quantified by RIA in the ovarian culture medium as described previously (Roman et al 2005, Ricci et al 2006. Antisera were kindly provided by Dr G D Niswender (Colorado State University, Fort Collins, CO, USA).…”

Section: Hormone Assaysmentioning

confidence: 99%

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Leptin modulates the expression of its receptors in the hypothalamic–pituitary–ovarian axis in a differential way

Yorio¹,

Bilbao²,

Pustovrh³

et al. 2008

Journal of Endocrinology

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To investigate the expression of leptin receptors (Ob-R) in the rat hypothalamus-pituitary-ovarian axis, immature rats were treated with eCG/hCG and Ob-R expression was evaluated by western blot analysis. The Ob-R expression increased 24 h after eCG administration in all the tissues assayed. In the hypothalamus, these levels immediately decreased to those obtained without treatment. In the pituitary, the Ob-R expression continued to be elevated 48 h after eCG administration, whereas the hCG injection did not modify these levels. Similar results were obtained with the ovarian long isoform. To assess the effect of leptin on its receptors, Ob-R was assessed in hypothalamus, pituitary and ovarian explants cultured in the presence or absence of leptin (0 . 3-500 ng/ml). In the hypothalamus, we found a biphasic effect: the Ob-R expression was either reduced or increased at low or high concentrations of leptin respectively. LH-releasing hormone secretion increased at 1 ng/ml. In the pituitary, Ob-R increased at 10 or 30 ng/ml of leptin for the long and short isoforms respectively. Leptin also induced an increase in LH release at 30 ng/ml. In the ovarian culture, the presence of leptin produced an increase in Ob-R expression at different ranges of concentrations and a dosedependent biphasic effect on the progesterone production. In conclusion, all these results clearly suggest that leptin is able to modulate the expression of its own receptors in the reproductive axis in a differential way. Moreover, the positive or negative effect that leptin exerts on the ovulatory process may be dependent on this regulation.

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Section: Introductionmentioning

confidence: 59%

Section: Discussionmentioning

confidence: 97%

Section: Ctrlmentioning

confidence: 96%

Section: In Vivo Studiesmentioning

confidence: 99%

Section: Hormone Assaysmentioning

confidence: 99%

See 3 more Smart Citations

Leptin modulates the expression of its receptors in the hypothalamic–pituitary–ovarian axis in a differential way

Yorio¹,

Bilbao²,

Pustovrh³

et al. 2008

Journal of Endocrinology

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Leptin and its associations with measures of psychopathology in patients with anorexia nervosa

et al. 2008

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Apart from energy homeostasis leptin has been shown to be involved in a number of neuronal networks. The aim of this study was to investigate how the residual variance of leptin levels, after controlling for BMI, is linked to eating-disorder-specific psychopathology and sexual desire in patients with anorexia nervosa (AN) compared to healthy controls. The sample included 57 subjects with acute AN and 77 healthy controls. Psychopathology was determined by EDI-2 and SCL-90-R and sexual problems were rated according to the Structured Interview of Anorexia Nervosa and Bulimic Syndromes (SIAB-EX). Plasma leptin was assessed by ELISA. Patients with a high drive for thinness had lower leptin levels at a given BMI and low leptin levels were associated with sexual problems, i.e. the absence of sexual desire and intimate relationships. Our results are in accordance with recent animal experiments linking low leptin levels with decreased sexual interest irrespective of body weight.

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Neuroendocrine disturbances in women with functional hypothalamic amenorrhea: an update and future directions

Męczekalski,

Niwczyk,

Battipaglia

et al. 2023

Endocrine

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Functional hypothalamic amenorrhea (FHA) is one of the most common causes of both primary and secondary amenorrhea in women of reproductive age. It is characterized by chronic anovulation and the absence of menses that appear as a result of stressors such as eating disorders, excessive exercise, or psychological distress. FHA is presumed to be a functional disruption in the pulsatile secretion of hypothalamic gonadotropin-releasing hormone, which in turn impairs the release of gonadotropin. Hypoestrogenism is observed due to the absence of ovarian follicle recruitment. Numerous neurotransmitters have been identified which play an important role in the regulation of the hypothalamic-pituitary-ovarian axis and of which the impairment would contribute to developing FHA. In this review we summarize the most recent advances in the identification of contributing neuroendocrine disturbances and relevant contributors to the development of FHA.

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Leptin enhances ovulation and attenuates the effects produced by food restriction

Cited by 32 publications

References 46 publications

Leptin modulates the expression of its receptors in the hypothalamic–pituitary–ovarian axis in a differential way

Leptin modulates the expression of its receptors in the hypothalamic–pituitary–ovarian axis in a differential way

Leptin and its associations with measures of psychopathology in patients with anorexia nervosa

Neuroendocrine disturbances in women with functional hypothalamic amenorrhea: an update and future directions

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