Gonadal hormones

Along with the increasing application of nanoparticles (NPs) in many walks of life, environmental exposure to NPs has raised considerable health concerns. When NPs enter a pregnant woman's body through inhalation, venous injection, ingestion or skin permeation, maternal toxic stress reactions such as reactive oxygen species (ROS), inflammation, apoptosis and endocrine dyscrasia are induced in different organs, particularly in the reproductive organs. Recent studies have shown that NPs disturb the developing oocyte by invading the protective barrier of theca cells, granulosa cell layers and zona pellucida...

The activity of the hypothalamo-pituitary gonadal (HPG) axis is influenced by energy reserves, such that an increase or a decrease in adiposity may perturb the secretion and action of GnRH. This is thought to be due to the signalling of hormones such as leptin, which act upon neuronal systems controlling GnRH secretion. Other work shows plasticity in the relationship between tanycytes and GnRH neurosecretory terminals in the median eminence across the estrous cycle and we hypothesised that similar plasticity may occur with altered metabolic status...

A 19-year-old woman with a history of isosexual precocious puberty and bilateral oophorectomy at age 10 years because of giant ovarian cysts, presents with headaches and mild symptoms and signs of hyperthyroidism. Hormonal evaluation revealed elevated FSH and LH levels in the postmenopausal range and free hyperthyroxinemia with an inappropriately normal TSH. Pituitary MRI showed a 2-cm macroadenoma with suprasellar extension. She underwent successful surgical resection of the pituitary tumor, which proved to be composed of two distinct populations of cells, each of them strongly immunoreactive for FSH and TSH, respectively...

Vitamin A (retinol) is a micronutrient critical for cell proliferation and differentiation. In adults, vitamin A and metabolites such as retinoic acid (RA) play major roles in vision, immune and brain functions, and tissue remodelling and metabolism. This review presents the physiological interactions of retinoids and endocrine tissues and hormonal systems. Two endocrine systems have been particularly studied. In the pituitary, retinoids targets the corticotrophs with a possible therapeutic use in corticotropinomas...

BACKGROUND: Though voluntary wheel running (VWR) has been used extensively to induce changes in both behavior and biology, little attention has been given to the way in which different variables influence VWR. This lack of understanding has led to an inability to utilize this behavior to its full potential, possibly blunting its effects on the endpoints of interest. NEW METHOD: We tested how running experience, sex, gonadal hormones, and wheel apparatus influence VWR in a range of wheel access "doses"...

Prophylactic gonadectomy has been recommended in complete androgen insensitivity syndrome (CAIS) because of an increased risk for the development of malignant germ cell tumors in the intra-abdominal gonads. No reliable screening parameters are available to detect early (pre-)malignant changes. Because the tumor risk before puberty is very low, the timing of gonadectomy has been postponed to allow spontaneous puberty and involvement of the patients in important decisions affecting their body and health. Gonadectomy after puberty is still discussed controversially...

The abuse of anabolic androgenic steroids (AAS) has been considered a major public health problem during decades. Supraphysiological doses of AAS may lead to a variety of neuroendocrine problems. Precisely, the hypothalamic-pituitary-gonadal (HPG) axis is one of the body systems that is mainly influenced by steroidal hormones. Fluctuations of the hormonal milieu result in alterations of reproductive function, which are made through changes in hypothalamic neurons expressing gonadotropin-releasing hormone (GnRH)...

Complete androgen insensitivity syndrome (CAIS) is due to complete androgen resistance in androgen-dependent tissues. Since androgens are involved in growth, development, and mass maintenance of the skeleton, bone health may be a relevant clinical issue for improving quality of life of women living with CAIS. Bone mineral density (BMD) in women with CAIS and intact gonads has been reported in a normal range, although exceptions are known showing a low BMD mainly at the lumbar level. In women with CAIS and removed gonads, BMD is usually reduced at both the lumbar spine and femoral neck...

The aim of the present study was to assess systematically gender differences in susceptibility to frailty and cognitive performance decline, and the underlying mechanisms. A systematic assessment was performed of the identified reviews of cohort, mechanistic and epidemiological studies. The selection criteria of the present study included: i) Sexual dimorphism of frailty, ii) sexual dimorphism of subjective memory decline (impairment) and atrophy of hippocampus during early life, iii) sexual dimorphism of late‑onset Alzheimer's disease and iv) sexual dimorphism mechanisms underlying frailty and cognitive impairment...

OBJECTIVE: Because age affects hormonal production differently in women compared with men, we sought to define sex and age interactions across a multiracial/ethnic population after intracerebral hemorrhage (ICH) to uncover evidence that loss of gonadal hormone production would result in loss of the known neuroprotective effects of gonadal hormones. METHODS: Clinical and radiographic data from participants in the Ethnic/Racial Variations of Intracerebral Hemorrhage study and the Genetic and Environmental Risk Factors for Hemorrhagic Stroke study prior to December 2013 were used...

Menopause is a process characterized by a decline in estrogen levels and is therefore a period of biological vulnerability for psychotic relapse in women with schizophrenia. Our goal was to correlate not only gonadal hormone levels but also follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels with improvement in specific clinical symptoms. Thirty-seven acutely ill postmenopausal schizophrenia women with a newly initiated, clinically determined change in antipsychotic medication participated in a 12-week prospective observational outcome study...

Bisphenol A (BPA) is a well-known endocrine disrupting chemical (EDC) that is used to manufacture plastic consumer products. It is well known that exposure to BPA can induce defects in gonad development and negatively influences reproductive function in both males and females. In this study, we assessed the effects of BPA on hormone production in Leydig cells, which secrete hormones in the testes and support male fertility. We examined two steroidogenic enzymes, CYP11A1 and CYP19 that involved in sex hormone synthesis in mouse MA-10 Leydig cells...

Adolescent social interactions can have long-term effects on physiological responses to stressors in later-life. A larger adolescent group size can result in higher stressor-induced secretion of glucocorticoids in adulthood. The effect may be due to a socially-mediated modulation of gonadal hormones, e.g. testosterone. However, group size (number of animals) has been conflated with social density (space per animal). Therefore it is hard to determine the mechanisms through which adolescent group size can affect the stress response...

BACKGROUND: The thermoneutral zone (TNZ) is a species-specific range of ambient temperature (T a), at which mammals can maintain a constant body temperature with the lowest metabolic rate. The TNZ for an adult mouse is between 26 and 34 °C. Interestingly, female mice prefer a higher T a than male mice although the underlying mechanism for this sex difference is unknown. Here, we tested whether gonadal hormones are dominant factors controlling temperature preference in male and female mice...

Genetic influences on disordered eating (DE) increase across age and puberty in girls, an effect that is at least partially due to ovarian hormone activation. However, development shifts in genetic effects have not been detected in boys; genetic influences have been found to be relatively constant from prepuberty to adulthood, suggesting that gonadal hormones may be less important. One caveat is that studies have examined males ages 10 or older. Genetic effects on DE may emerge earlier in boys, such as during adrenarche, when androgens begin to increase but the physical changes of puberty are not yet observable...

BACKGROUND: Maladaptive responses to negative affective stimuli are pervasive, including clinically ill and healthy people, and men and women respond differently at neural and hormonal levels. Inspired by the Research Domain Criteria initiative, we used a transdiagnostic approach to investigate the impact of sex and dysphoric mood on neural-hormonal responses to negative affective stimuli. METHODS: Participants included 99 individuals with major depressive disorder, psychosis and healthy controls...

Sex assignment in 46XY genetic male children with congenital inadequacy of the penis (CIP) is controversial. Traditionally, children with penile length less than 2 cm at birth are considered unsuitable to be raised as males. They are typically re-assigned to female-sex and feminizing genitoplasty is usually done in infancy. However, the concept of cerebral androgen imprinting has caused paradigm shift in the philosophy of sex re-assignment. Masculinization of the brain, rather than length of the penis, is the modern criterion of sex re-assignment in CIP...

In vertebrates, exposure to acute stressors stimulates the secretion of adrenal glucocorticoids such as corticosterone, and in some situations this hormone plays an important role in orchestrating the trade-off that exists between reproduction and self-maintenance. Stressful conditions often lead to a decrease in plasma levels of sex steroids such as testosterone in males, and it has been hypothesized that corticosterone contributes to this decrease. Generally supporting this proposition, glucocorticoids can inhibit the reproductive axis activity at multiple levels, including direct effects on testicular endocrine function...

AIM: Childhood brain tumour survivors have a high risk of endocrine morbidity. This study evaluated the growth, pubertal development and gonadal function in survivors of childhood brain tumours and identified factors associated with the problems we observed. METHODS: The 52 subjects (52% male) were diagnosed in 1983-1997 and treated for brain tumours at Tampere University Hospital, Finland. They were followed up at a mean age of 14.2 (3.8-28.7) years, a mean of 7...

RATIONALE: Altered glutamate NMDA receptor function is implicated in schizophrenia, and gender differences have been demonstrated in this illness. OBJECTIVES: This study aimed to investigate the interaction of gonadal hormones with NMDA receptor-mediated locomotor hyperactivity and PPI disruption in mice. RESULTS: The effect of 0.25 mg/kg of MK-801 on locomotor activity was greater in male mice than in female mice. Gonadectomy (by surgical castration) significantly reduced MK-801-induced hyperlocomotion in male mice, but no effect of gonadectomy was seen in female mice or on amphetamine-induced locomotor hyperactivity...