Antidiuretic hormone ADH secretion

Vasopressin (antidiuretic hormone [ADH]) secretion increases in response to decreased blood volume and/or reductions in effective blood volume via a decrease in inhibitory tone from both low-pressure and high-pressure baroreceptors to the hypothalamus. The neuronal pathways that mediate hemodynamic regulation of... 

Metabolism fever and chills, syndrome of inappropriate antidiuretic hormone (ADH) secretion. 

Fluid is also lost through the kidneys, a process which is regulated by antidiuretic hormone (ADH). Secretion of large amounts of ADH results in more water reabsorption by the renal tubules and the formation of a concentrated urine. Decreased secretion of ADH results in less water reabsorption and a dilute urine being produced. 

The permeability properties of the distal convoluted tubule are regulated by antidiuretic hormone (ADH, or vasopressin). In hypotonic conditions, ADH secretion by the posterior pituitary is suppressed and the distal convoluted tubule is impermeant to water. Conversely, in hypertonic or volume-contracted states, ADH is released by the posterior pituitary and increases the permeability and water reabsorption by the distal convoluted tubule. 

The posterior lobe secretes two hormone namely oxytocin and antidiuretic hormone (ADH or vasopressin). 

The syndrome of inappropriate antidiuretic hormone (SIADH) secretion is a condition in which secretion of ADH continues despite serum hypo-osmolarity. This results in fluid retention and hyponatremia that can lead to brain oedema, mental confusion and coma. The causes are hypothalamic-pituitary tumours or an ectopic vasopressin-secreting tumour. 

Posterior Lobe. The posterior pituitary, or neuro-hypophysis, secretes two hormones antidiuretic hormone (ADH) and oxytocin.2 12 ADH exerts its effect... 

Diabetes mellitus is a disease caused by insufficient insulin secretion or a decrease in the peripheral effects of insulin. This disease is characterized by a primary defect in the metabolism of carbohydrates and other energy substrates. These metabolic defects can lead to serious acute and chronic pathologic changes. The term diabetes mellitus differentiates this disease from an unrelated disorder known as diabetes insipidus. Diabetes insipidus is caused by a lack of antidiuretic hormone (ADH) production or insensitivity to ADH. Consequently, the full terminology of diabetes mellitus should be used when referring to the insulin-related disease. Most clinicians, however, refer to diabetes mellitus as simply diabetes. ... 

A key determinant of the final urine concentration is antidiuretic hormone (ADH also called vasopressin). In the absence of ADH, the collecting tubule (and duct) is impermeable to water, and dilute urine is produced. However, membrane water permeability of principal cells can be increased by ADH-induced fusion of vesicles containing preformed water channels with the apical membranes (Figure 15-6). ADH secretion is regulated by serum osmolality and by volume status. 

Hyponatremia is caused by an excess of total body water relative to total body sodium and can result from a number of underlying conditions, including the syndrome of inappropriate antidiuretic hormone secretion (SIADH), cirrhosis, and congestive heart failure (CHF). In each of these conditions, inappropriate production of arginine vasopressin (AVP) [also known as vasopressin or antidiuretic hormone (ADH)], a neurohormone that regulates renal electrolyte-free water reabsorption, contributes to enhanced renal water retention, leading to decreased serum sodium concentrations.7 Hyponatremia can be characterized as hypervolemic, euvolemic, or hypovolemic... 

The principal and intercalated cells of the collecting tubule aie responsible for Na+- K+ exchange and for H+ secretion and K+ reabsorption, respectively. Stimulation of aldosterone receptors in the principal cells results in Na+ reabsorption and K+ secretion. Antidiuretic hormone (ADH, vasopressin) receptors promote the reabsorption of water from the collecting tubules and ducts (Figure 23.3). This action is mediated by cAMP. 

The pituitary gland secretes growth hormone (GH), antidiuretic hormone (ADH), and oxytocin. 

The adenohypophysis secretes growth hormone (GH), prolactin (PRL), thyrotropin (TSH), adrenocorticotropin (ACTH), foUicle-stimulating hormone (FSH), and luteinizing hormone (LH), all of which are proteins or peptides (see Table 28-1 in Chapter 28). It also secretes P-lipotropin (P-LPH) and a number of smaller peptides of undetermined significance Vasopressin (also known as antidiuretic hormone [ADH]) and oxytocin are produced in the hypothalamus and are carried through the neurohypophyseal nerve axons to the neurohypophysis. Thus the neurohypophysis is not a discrete endocrine organ, but rather functions as a reservoir for these two hormones. 

Antidiuretic hormone (ADH) is released from the posterior pituitary when the plasma osmolahty rises by 1% to 2% or more. ADH binds to the vasopressin-2 (V2) receptors on the basolateral surface of renal tubular epithelial cells, and through a series of second messenger reactions, a water channel (aquaporin-2) is inserted into the apical tubular lumen surface of the cell. Water may then pass through the cell into the peritubular capillary space, and is then reabsorbed into the systemic circulation. A rise in serum osmolality sensed in the hypothalamus results not only in ADH release, but also in stimulation of thirst. The combination of an increase in water intake and a decrease in water excretion results in a decrease in the serum osmolality and inhibition of ADH secretion once the plasma osmolality is restored to normal. 

One of the posterior pituitary hormones—antidiuretic hormone (ADH, vasopressin)—may play a part in the metabolic response to injury. The reduced blood volume and increased plasma electrolyte concentration found after trauma may be expected to stimulate ADH secretion and the oliguria or anuria often found to follow injury would surest this is so (J2). 

Studies have shown that, in addition to the conventional peptide hormones of pancreatic islets (insulin, glucagon, somatostatin, and pancreatic polypeptide), these tumors can also secrete (and express) ectopic peptides, in particular gastrin and VIP (vasoactive intestinal peptide),but on occasion also ACTH (adrenal corticotropic hormone),antidiuretic hormone (ADH), MSH (melanocyte-stimulating hormone), calcitonin, neurotensin, secretoneurin, 754-356 PTH (parathyroid hormone-like peptide),growth hormone and growth hormone releasing factor, secretogranin inhibin/activin, i prohormone... 

The posterior pituitary gland secretes two hormones, antidiuretic hormone (ADH) and oxytocin. They are both synthesized in the hypothalamus and reach the posterior pituitary via a neural connection. See Figure 6.2. 

Chlorpromazine may have weak diuretic effects because of a depressant action on the secretion of vasopressin (antidiuretic hormone, ADH), inhibition of reabsorption of water and electrolytes by a direct action on the renal tubule, or both. The syndrome of idiopathic polydipsia and hyponatremia sometimes associated with psychotic illness has respotuled to clozapine, presumably via... 

The posterior pituitary gland secretes antidiuretic hormone (ADH) and oxytocin. ADH is a vasopressin. Ox5docin is released to start labor contractions. ADH promotes water reabsorption from the renal tubules to maintain water balance in the body s fluids. A deficiency of ADH, called diabetes insipidus (Dl), causes the kidneys to excrete large amounts of water. This leads to severe fluid volume deficit and electrol5de imbalances. 

Extracellular fluid balance is maintained through closely regulated loss and retention to ensure that the total level of fluid in the body remains constant. Mechanisms are in place for regulation of water loss, such as secretion of antidiuretic hormone (ADH) to stimulation retention of water in urine, which helps to prevent excessive fluid elimination. The mechanism of thirst (also stimulated by ADH, as well as by blood pressure) is used to stimulate the ingestion of fluids and fluid-containing foods. 3... 

Antidiuretic hormone promotes the reabsorption of water from the tubules of the kidney, or antidiuresis. Specifically, it acts on the collecting ducts and increases the number of water channels, which increases the diffusion coefficient for water. This results in the body s conservation of water and the production of a low volume of concentrated urine. The reabsorbed water affects plasma osmolarity and blood volume. This effect of ADH on the kidney occurs at relatively low concentrations. At higher concentrations, ADH causes constriction of arterioles, which serves to increase blood pressure. Antidiuretic hormone secretion is regulated by several factors ... 

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