Endocrine Abstracts

The hypothalamo-pituitary-thyroid axis undergoes adaptive changes in response to increased energy expenditure at puberty, a process called thyroidarche. Furthermore, the secretion of thyroid hormones (THs) is influenced by various kinds of acute and chronic stresses. Amongst others, persistent and severe physical stress may affect the secretion of THs. The present study investigates changes in the secretion of thyrotropin releasing hormone (TSH), trioiodothyronine (T3) and tet...

The reawakening of the hypothalamo-pituitary-gonadal (HPG) leading to attainment of sexual maturation and reproductive capacity is influenced by several internal and external factors. Amongst external factors, adverse physical or psychological conditions may alter the timing of onset of puberty. The present study examined the effect of persistent and severe physical stress on timing of onset of puberty. The study included non-working school/college going and working boys of 10...

Adrenarche is a normal maturational event that in humans occurs at around 6–8 years of age. During adrenarche, a new zone of the adrenal cortex, the zona reticularis, is developed, resulting in increased production of adrenal androgens, androsteindione, DHEA and DHEAS. The increase in the secretion of adrenal androgens causes the appearance of axilliary and pubic hair, a brief increase in linear growth velocity and bone maturation, and the development of the brain. The pr...

The oxyntic mucosa of digestive tract secretes two peptide hormones, ghrelin and obestatin, which are derived from the same gene transcript and play an important role in food intake, metabolic responses and growth and reproduction. Ghrelin and obestatin bind GH secretagogue receptor GHSR1α and G-protein coupled receptor GPR39 respectively, in the pituitary. A limited data in the literature demonstrate that levels of ghrelin peak during first 2 years of life and thereafter...

Ghrelin receptor GHSR1α is expressed in hypothalamo–pituitary–gonadal tissues. Ghrelin reduces GnRH secretion in pre-pubertal period and concentrations of ghrelin are positively correlated with testosterone at adulthood. Nevertheless, the role of ghrelin in affecting pituitary and gonadal functions during normal pubertal development remains elusive. A possible correlation between ghrelin and LH, FSH, testosterone and inhibin B was examined in boys (n=55...

The G protein coupled receptor of obestatin GPR39 is expressed in pituitary and gonads, indicating its possible role in regulation of pituitary and testicular function. The present study examined a possible association of obestatin with LH, FSH, testosterone, and inhibin B at puberty. Blood samples were collected from 10 to 20 years old boys (n=557) and concentrations of obestatin, LH, FSH, testosterone, and inhibib B were determined using specific ELISA. Data were an...

Leptin, a key metabolic signal controlling both energy intake and energy reserves, informs the brain about energy stores of the body to initiate reproductive processes at puberty. Thyroid hormones are important determinant of overall energy expenditure, basal metabolic rate and thermogenesis. The present study examined the relationship between leptin and thyroxine (T4) and triiodothyronine (T3) in boys (n=540) between the age of 1 and 20 years. B...

Ghrelin, a putative signal of insufficient energy stores, increases in fasting states, decreases postprandially, and acts as a potent appetite stimulant increasing food intake. Obestatin affects appetite, food preferences to increase daily caloric intake and weight gain. Leptin regulates body fat mass, food intake and energy expenditure. Triiodothyronine (T3) is a determinant of adiposity, thermogenesis, glucose and lipid metabolism, appetite, food intake, and the o...

Congenital adrenal hyperplasia (CAH), caused by lack of 21-hydroxylase, impairs cortisol secretion, which increases ACTH release that results in hyperplasia of adrenal glands and increased secretion of adrenal androgens. Elevated androgen concentration leads to increased skeletal maturation, early pubertal development and diminished pubertal growth. Treatment with glucocorticoids averts early puberty but may abruptly slow down growth. The effect of exogenous glucocorticoids on...

The signaling of G protein-coupled receptor 54 (GPR54) is a key regulator of the secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamic GnRH neurons, whereas GnRH is a crucial neurohormone regulating the secretion of FSH and LH at the time of puberty. The deficiency in the release or action of GnRH leads to hypogonadotropic hypogonadism (HH) characterized by low FSH, LH and testosterone (T) and results in absent or impaired sexual development at puberty. In b...