OBJECTIVES: Polycystic ovary syndrome is a heterogeneous endocrine disorder that affects reproductive-age women. The mechanisms underlying the endocrine heterogeneity and neuroendocrinology of polycystic ovary syndrome are still unclear. In this study, we investigated the expression of the kisspeptin system and gonadotropin-releasing hormone pulse regulators in the hypothalamus as well as facto...

OBJECTIVE Premature thelarche (PT) is defined as isolated breast development without secondary sex characteristics in girls below the age of eight. We aimed to determine whether the level of kisspeptin, which plays a role in the release of gonadotropins, is associated with PT. METHODS The patient group included children with PT aged 3-8 years (n=20) and the control group included healthy chil...

The posterodorsal medial amygdala (MePD) is a neural site in the limbic brain involved in regulating emotional and sexual behaviours. There is, however, limited information available on the specific neuronal cell type in the MePD functionally mediating these behaviours in rodents. The recent discovery of a significant kisspeptin neurone population in the MePD has raised interest in the possible...

Hypothalamic kisspeptin (Kiss1) neurons express estrogen receptor α (ERα) and exert control over GnRH/LH secretion in female rodents. It has been proposed that estradiol (E2) activation of ERα in kisspeptin neurons in the arcuate nucleus (ARC) suppresses GnRH/LH secretion (negative feedback), whereas E2 activation of ERα in kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) ...

Gonadotropin-releasing hormone (GnRH) secretion is regulated by estradiol feedback. This feedback switches from negative to positive in females; this switch depends on time of day in many species. Estradiol feedback is likely conveyed via afferents. Kisspeptin neurons of the arcuate nucleus and anteroventral-periventricular region (AVPV) may differentially regulate GnRH neurons during negative ...

Background: Hypothalamus-derived kisspeptins are critical regulators of reproduction in nearly all mammalian species including the humans. These small peptides mediate their actions through the GnRH loop system. How kisspeptins regulate gonadal maturation in sexually immature male mammals remains elusive. To address this, kisspeptin was administered as subchronic (12 days) twice daily i. p. dos...

BACKGROUND The discovery of kisspeptin as key central regulator of GnRH secretion has led to a new level of understanding of the neuroendocrine regulation of human reproduction. The related discovery of the kisspeptin-neurokinin B-dynorphin (KNDy) pathway in the last decade has further strengthened our understanding of the modulation of GnRH secretion by endocrine, metabolic and environmental i...

The discovery of the neuropeptide kisspeptin, originally derived from its antimetastatic property affecting malignant melanoma cells, as well as its role in reproductive function, was a milestone in the field of reproductive biology. Conventionally, the capacity for reproductive activity in mammals involves coordinated communication between the hypothalamus, the anterior pituitary, and the gona...