Endocrine Abstracts

The heart not only has a mechanical function of pumping blood through vessels but also acts as an endocrine gland. In its endocrine function, the heart releases atrial natriuretic peptide (ANP), a hormone of a large family of natriuretic peptides. ANP is secreted from cardiac atria as an inactive preprohormone. In post-translational modification, 25-amino acid signal sequence is cleaved from preprohormone to produce proANP of 126-amino acid, which is the major form of ANP stor...

Hypertension is associated with vascular changes characterized by endothelial dysfunction, increased vascular contraction, and arterial remodelling. Vascular smooth muscle (VSM) cells, which constitute bulk of vascular wall, are critically involved in these processes through their highly plastic and dynamic features and ability to undergo phenotypic differentiation. Stimulation of VSM cells by pro-hypertensive neurohumoral stimuli such as acetylcholine and norepinephrine, and ...

Evidence indicates that normal pattern of progression of puberty is altered under certain conditions of stress, whereas growth rate is affected by sustained higher concentrations of cortisol, a marker of stress reactivity. Available data show that early teens commonly resort to use of drugs. The use of drugs may evoke stress responses, which may alter pubertal development and affect growth rate. Body weight (BW), height, BMI and plasma concentrations of LH, testosterone (T), G...

The secretion of leptin, an indicator of energy reserves, declines as energy stores are consumed in growth and development at puberty. The pubertal growth and development are often altered under different kinds of stresses. Usually, stress stimulates the release of cortisol, which is a labelled marker of stress. Early teens are inclined to drug abuse that may put their bodies under stress and may induce excessive secretion of cortisol. Since, sustained high levels of cortisol ...

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...

The renin-angiotensin-aldosterone system (RAAS) is an endocrine system within the body that is essential for regulation of blood pressure (BP) and fluid balance. The system is mainly comprised of three hormones renin, angiotensin II (Ang II) and aldosterone. The RAAS pathway is initiated in the kidney with the proteolytic conversion of liver derived angiotensinogen to angiotensin I (Ang I) by renin secreted by juxtaglomerular apparatus of the nephron. Ang I is cleaved by angio...

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...

Thyroid gland secretes thyroid hormones, which play a critical role in growth, differentiation, reproduction and metabolism, whereas hypothyroidism in children is associated with short stature and normalisation of thyroid function with thyroxin replacement therapy increases linear growth velocity (LGV). In stimulating LGV, thyroxin may have its direct effects on bone cells or it may affect LGV through its effect on growth hormone (GH) secretion. The present study attempted to ...

In GH deficiency (GHD), which is a medical condition caused by problems in the pituitary gland, the body does not produce sufficient amount of GH, resulting in short stature in children. The treatment of GHD short children with exogenous GH increases linear growth velocity (LGV). The present study determined the effect of exogenous GH treatment on LGV, the dose(s) of exogenous GH that effectively impacts LGV and the stage(s) of puberty at which the effect of exogenous GH treat...