Studies on the Character of Hypothalamic GnRH Neurons and Kisspeptin Neurons Using Hypothalamic Cell Models

The hypothalamic-pituitary-gonadal (HPG) axis controls the hormonal network responsible for reproductive functions. In the past, hypothalamic gonadotropin-releasing hormone (GnRH) neurons have been positioned at the highest level in the HPG axis. After the discovery of the indispensable roles of hypothalamic kisspeptin in GnRH neurons, our understanding of the neuroendocrine regulation of the HPG axis was reconfirmed, and it is now recognized that hypothalamic kisspeptin neurons are positioned at the summit of the HPG axis. Accumulating evidence shows that kisspeptin neurons are responsible for the onset of puberty and sex steroid feedback mechanisms by modulating the activity of GnRH neurons. Furthermore, the identification of kisspeptin in the hypophyseal portal circulation suggests that this peptide has some direct roles in the pituitary gland. The detailed mechanisms underlying the regulation of GnRH by kisspeptin and the regulatory control of kisspeptin neurons are still largely unknown because of the limitations of the experimental models. The establishment of GnRH-expressing and kisspeptin-expressing cell models has enabled us to examine the character of these neuronal cells. In this chapter, we describe our in vivo studies examining the character of GnRH neurons and kisspeptin neurons in the hypothalamus using hypothalamic GnRH- and/or kisspeptin-expressing cell models

Extracellular Signal-Regulated Kinase (ERK) Activation and Mitogen-Activated Protein Kinase Phosphatase 1 Induction by Pulsatile Gonadotropin-Releasing Hormone in Pituitary Gonadotrophs

The frequency of gonadotropin-releasing hormone (GnRH) pulse secreted from the hypothalamus differently regulates the expressions of gonadotropin subunit genes, luteinizing hormone β (LHβ) and follicle-stimulating hormone β (FSHβ), in the pituitary gonadotrophs. FSHβ is preferentially stimulated at slower GnRH pulse frequencies, whereas LHβ is preferentially stimulated at more rapid pulse frequencies. Several signaling pathways are activated, including mitogen-activated protein kinase (MAPK), protein kinase C, calcium influx, and calcium-calmodulin kinases, and these may be preferentially regulated under certain conditions. Previous studies demonstrated that MAPK pathways, especially the extracellular signal-regulated kinase (ERK), play an essential role for induction of gonadotropin subunit gene expression by GnRH, whereas, MAPK phosphatases (MKPs) inactivate MAPKs through dephosphorylation of threonine and/or tyrosine residues. MKPs are also induced by GnRH, and potential feedback regulation between MAPK signaling and MKPs within the GnRH signaling pathway is evident in gonadotrophs. In this paper, we reviewed and mainly focused on our observations of the pattern of ERK activation and the induction of MKP by different frequencies of GnRH stimulation.</jats:p

Oral medications including clomiphene citrate or aromatase inhibitors with gonadotropins for controlled ovarian stimulation in women undergoing in vitro fertilisation

We thank:• Richard Kirubakaran, Cochrane South Asia, Prof. BV Moses Centre for Evidence-Informed Health Care and Health Policy, Christian Medical College, Vellore, India;• Marian Showell, Information Specialist for the Cochrane Gynaecology and Fertility Group;• Editorial team of the Cochrane Gynaecology and Fertility Group for their support and assistancePeer reviewedPublisher PD

The Creation of School Education Bringing up a Student Carrying Tomorrow (3) : The Valuation of "Compulsory Subjects", "Optional Subjects", and "Integrated Subjects"

The purpose of this study is to show the valuation of "Compulsory Subjects", "Optional Subjects", and "Integrated Subjects", to show the relationship between each subjects and "three abilities", "the ability of recognizing othere senses of value", "the ability of self-expression and communication" and "the ability of decision-making" which defined by the project members. The main result of this study is that we should make up the standards which teachers, students and parents recognize as important abilities

Is it Possible to Predict the Onset of Side Effects in Patients Treated with Subcutaneous Buserelin?

Buserelin acetate, a synthetic analog of gonadotropin-releasing hormone（GnRH）, is widely used　in the treatment of endometriosis and uterine leiomyoma.　This study sought to identify predictors　of side effects of buserelin treatment. The medical records of 52 patients who received buserelin treatment　were reviewed. The patients were divided into　two groups based on the presence or absence of the　common side effects of abnormal vaginal bleeding　and climacteric symptoms, and compared in terms of age, height, weight, BMI, and basal gonadotropin　level. Abnormal vaginal bleeding and climacteric　symptoms were reported in 69.2% and 61.5% of　the patients, respectively. Among patients who did　not report these side effects, mean weight and mean　BMI were significantly higher than those of patients　who reported the side effects. Mean basal level of　serum gonadotropins, the LH:FSH ratio, and patient menstrual history were not related to the incidence　of these side effects. Those with higher weight and　BMI are less likely to have buserelin effects, and　those with lower weight and BMI are more likely　to have these side effects. So, lower weight and BMI might be a predictors for two common side　effects of monthly buserelin treatment