Pituitary diabetes insipidus

Vasopressin and its derivatives are used in die treatment of diabetes insipidus, a disease resulting from die failure of the pituitary to secrete vasopressin or from surgical removal of die pituitary. Diabetes insipidus is characterized by marked increase in urination (as much as 10 L in 24 hours) and excessive tiiirst by inadequate secretion of die antidiuretic hormone or vasopressin. Treatment with vasopressin therapy replaces die hormone in the body and restores normal urination and thirst Vasopressin may also be used for die prevention and treatment of postoperative abdominal distention and to dispel gas interfering with abdominal roentgenography. 

Anti-diuretic hormone is a small peptide shown as Figure 8.9, which is secreted by the pituitary gland located at the base of the brain. The cellular actions of ADH are mediated by activation of a G-protein linked receptor generating cAMP as second messenger. Absence of ADH or a functional defect in the action of ADH-stimulated water reabsorption in the collecting duct results in the condition diabetes insipidus, characterized by the passing of large volumes (= diabetes) of dilute (= insipidus) urine. 

A second form of diabetes is also recognized diabetes insipidus, which is caused by a deficiency of the pituitary hormone, vasopressin. Vasopressin promotes water reabsorption from the kidney, hence a deficiency also induces S5anptoms of excessive urination and thirst. A key diagnostic difference between the common diabetes meUitus and the rare diabetes insipidus, is the absence of glucose in the urine in the latter case. Until a few decades ago, a popular way to differentiate between the two diseases was to taste the patient s urine to see if it was sweet. 

Deficiency of pituitary vasopressin (arginine vasopressin or AVP, also termed anti-diuretic hormone, ADH) causes the syndrome of polyuria, thirst and polydipsia termed cranial diabetes insipidus. It is... 

Chlorpropamide Diabinese) has a relatively slow onset of action, with its maximal hypoglycemic potential often not reached for 1 or 2 weeks. Similarly, several weeks may be required to eliminate the drug after discontinuation of therapy. This drug can cause flushing, particularly when taken with alcohol, and can also cause hyponatremia. This effect has been employed to treat some patients who have partial central diabetes insipidus, an unrelated condition due to a pituitary ADH deficiency. 

Diabetes insipidus They reduce urine volume in both pituitary and renal diabetes insipidus. They are especially valuable for the latter in which ADH is ineffective. 

The antidiuretic hormone is an octapeptide released from the posterior lobe of pituitary gland. It is used in the treatment of diabetes insipidus. ADH reduces the total urine volume and absence of this hormone cause diabetes insipidus. ADH acts on collecting duct cells to increase their water permeability. It acts on V2 receptors in collecting duct and regulate their water permeability through cAMP production. 

Antidiuretic hormone (ADH) Bovine posterior pituitaries Treatment of diabetes insipidus... 

Vasopressin and desmopressin are treatments of choice for pituitary diabetes insipidus. The dosage of desmopressin is 10-40 meg (0.1-0.4 mL) in two to three divided doses as a nasal spray or, as an oral tablet, 0.1-0.2 mg two to three times daily. The dosage by injection is 1-4 meg (0.25-1 mL) every 12-24 hours as needed for polyuria, polydipsia, or hypernatremia. Bedtime desmopressin therapy, by intranasal or oral administration, ameliorates nocturnal enuresis by decreasing nocturnal urine production. Vasopressin infusion is effective in some cases of esophageal variceal bleeding and colonic diverticular bleeding. 

Desmopressin Activates vasopressin V2 receptors much more than Vi Acts in the kidney to decrease the excretion of water acts on extrarenal V2 receptors Pituitary diabetes insipidus hemophilia A and von Willebrand disease Oral, IV, SC, or intranasal Toxicity Gastrointestinal disturbances, headache, hyponatremia, allergic... 

Rado JP. Evidence for permanent enhancement of residual ADH induced by antidiuretic agents (chlorpropamide, car-bamazepine, clofibrate) in patients with pituitary diabetes insipidus. Endokrinologie 1975 64(2) 217-22. 

Also known as water diabetes, diabetes insipidus (DI) is a rare chronic disease that causes excessive urination. If not properly treated, it can result in electrolyte imbalance and dehydration. It may be caused by a number of factors, including lithium use (a psychiatric drug used for bipolar disorder), neurological disease, or an inadequate amount of ADH (anti-diuretic hormone, or vasopressin, which is produced by the pituitary gland). DI caused by insufficient ADH is called central diabetes insipidus. 

Vasopressin and desmopressin are used in the treatment of pituitary diabetes insipidus. They are discussed in Chapter 37 Hypothalamic Pituitary Hormones. 

Vasopressin is a peptide hormone released by the posterior pituitary in response to rising plasma tonicity or falling blood pressure. Vasopressin possesses antidiuretic and vasopressor properties. A deficiency of this hormone results in diabetes insipidus (see Chapters 15 and 17). 

Vasopressin and desmopressin are the alternative treatments of choice for pituitary diabetes insipidus. Bedtime desmopressin therapy ameliorates nocturnal enuresis by decreasing nocturnal urine production. Vasopressin infusion is effective in some cases of esophageal variceal bleeding and colonic diverticular bleeding. 

Central diabetes insipidus A synthetic analog of the natural pituitary hormone 8-arginine vasopressin Lactose, potato starch, povidone, magnesium stearate Aventis... 

Vasopressin [vay soe PRESS in] (antidiuretic hormone, ADH), is structurally related to oxytocin (Figure 25.5). The chemically-synthesized nonapeptide has replaced that extracted from animal posterior pituitaries. Vasopressin has both antidiuretic and vasopressor effects. In the kidney it binds to the V2 receptor to increase water permeability and resorption in the collecting tubules. Thus the major use of vasopressin is to treat diabetes insipidus. It also finds use in controlling bleeding due to esophageal varices or colonic diverticula. Other effects of vasopressin are mediated by the Vi receptor, found in vascular smooth muscle, liver and other tissues. As might be expected the major toxicity is water intoxication and hyponatremia. Headache, bronchoconstriction and tremor also can occur. Caution must be used in treating patients with coronary artery disease, epilepsy and asthma. 

Non-plant reference [Vasopressin] (lOkDa 9aa 2 Cys 1 S-S peptide) Animals ex posterior pituitary nephrogenic diabetes insipidus from V2 VAS-R mutation 5.8Xn VAS-R agonist [kidney distal tubule water reabsorption per aquaporins, vasoconstrictor]... 

The term diabetes is usually taken to refer to diabetes mellitus, which is associated with excessive sweet urine (known as glycosuria ). Rarer diabetic conditions include diabetes insipidus, where the urine is not sweet this can be caused by either kidney or pituitary gland damage. 

Hypothalamic ( central ) diabetes insipidus. This results from a deficiency in secretion of antidiuretic hormone from the posterior pituitary. Causes may include head trauma, infections or tumours involving the hypothalamus. 

For replacement therapy of pituitary diabetes insipidus the longer acting analogue desmopressin is used. 

Chlorpropamide (but not other sulphonylureas) and carbamazepine are effective in partial pituitary diabetes insipidus, i.e. some natural hormone production remains, because they act on the kidney potentiating the effect of vasopressin on the renal tubule. H5q oglycaemia may occur with chlorpropamide. 

Oxytocin is a peptide hormone of the posterior pituitary gland. It stimulates the contractions of the pregnant uterus, which becomes much more sensitive to it at term. Patients with posterior pituitary disease (diabetes insipidus) can, however, go into labour normally. 

ADH is therapeutically useful in the treatment of diabetes insipidus of pituitary origin. It also has been ased to relieve inte.stinal paresis and distention. 

DIABETES INSIPIDUS TREATMENT involves the administration of drugs to counteract the under-production of antidiuretic hormone (ADH vasopressin) by the pituitary gland, which is a characteristic of diabetes insipidus. ADH itself (arginine vasopressin or lysine vasopressin) can be used, as can the analogues desmopressin and terlipressin. These are all (V subtype) VASOPRESSIN RECEPTOR AGONISTS. These agents are discussed... 

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