Endocrine Abstracts

Arginine vasopressin (AVP) is a neurohormone, which regulates blood and extracellular fluid volume and hence blood pressure (BP). AVP has its chief action in kidneys where it reduces flow of urine, increases permeability of convoluted tubules of kidneys to water and its reabsorption. It binds to receptors on sweat glands and decreases water loss by perspiration from the skin. Also, AVP binds to peripheral arteriolar receptors, causing vasoconstriction and increase in BP. The s...

Leptin is regarded as an essential adipokine for controlling energy homeostasis, caloric intake reduction and increase of caloric expenditure by negative feedback mechanisms via receptors in the hypothalamus. Puberty is said to be triggered by leptin, which signals the hypothalamus that adequate fat reserves are available for initiation of energetically costly process of reproduction. Leptin activates gonadotropin releasing hormone (GnRH) system, which stimulates luteinizing h...

During the time of puberty, thyroid hormones (THs), thyroxin (T4) and triiodothyronine (T3), influence growth and developmental processes by working in association with growth hormone (GH), insulin like growth factor-I (IGF-1), glucocorticoids, insulin and gonadal steroids. THs have a direct effect on GH secretion, which stimulates IGF system. It has been suggested that THs control increase in bone length through synergy with GH. This investigation determ...

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...

Hypertension or elevated blood pressure (BP) is quantitatively the most important risk factor for development of cardiovascular diseases (CVDs), whereas aldosterone contributes significantly in the development and severity of hypertension. Interestingly, parathyroid hormone (PTH) stimulates aldosterone synthesis by regulating renin-angiotensin-aldosterone system (RAAS). Conversely, RAAS controls PTH secretion, as angiotensin receptor is expressed by human parathyroid tissues a...

Diabetes mellitus type 2 (DM-2) occurs when pancreas fails to produce enough insulin or when the body cannot effectively make use of the insulin produced by the pancreas. Among other factors causing DM-2, stress is increasingly regarded as one of the causative agents that make the blood glucose levels rise, and cause DM-2. It has also been reported that DM-2 may be one of the commonest cause of hypogonadism, a lack of function in the testes, which adversely affects testosteron...

Hypertension or high blood pressure (HBP) has been counted as the chief cause and most significant factor in the development of cardiovascular diseases (CVDs) worldwide. Stress has been defined as an inner process that happens when a person is faced with an ordinant dictation that is perceived to go beyond the resources available to efficaciously respond to it. Cortisol is a hormone released from the zona fasciculata of the adrenal cortex during the times of stress. This biolo...

Diabetes mellitus type 2 (DM-2) is a disorder characterized by high blood glucose levels in the context of insulin resistance and relative insulin deficiency. DM-2 is typically an outcome of combinations of hereditary elements of impaired insulin release and insulin resistance, and natural variables like obesity, overeating, absence of activity, aging and stress. A number of hormones, such as cortisol and growth (GH), have insulin-antagonistic effects. Cortisol is a predominan...

The reawakening of hypothalamo-pituitary-gonadal axis at puberty is influenced by a number of hormonal and genetic factors along with certain environmental cues. In boys, puberty is initiated at around 9 years of age as plasma concentrations of luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone (T) begin to rise leading to development of secondary sex characteristics. The absence of signs of sexual maturation at the age of 14/15 years is regarded as ...

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...