Excessive secretion of ADH causes

ADH is due to have a kidney promotion of long tubular epithelial cells and collecting duct reabsorption of water, so a variety of causes excessive secretion of ADH, so that water can be discharged by the reduction in kidney, so that the body prone to water intoxication. ADH due to excessive secretion of ADH is to promote kidney tubules far collecting duct epithelial cells and re-absorption of water, so a variety of causes excessive secretion of ADH, so that water can be discharged by the reduction in kidney, so that the body prone to water Poisoning. Excessive secretion of ADH reason can be summarized in the following areas: ⑴ ADH secretion abnormal syndrome (Syndrome lf inappropriate ADH secretion, SIADH): Following is a disease found in certain cases: ① cancer: oat cell lung cancer, pancreatic cancer, Hodgkin's disease and lymphosarcoma, and so on; ② central nervous Diseases: such as brain tumor, brain abscess, subdural hemorrhage, subarachnoid hemorrhage, cerebral vascular thrombosis, bacterial or viral encephalitis, tuberculosis or bacterial meningitis, as well as Alzheimer's and so on; ③ pulmonary disease : Tuberculosis, pulmonary abscess, viral and bacterial pneumonia, and so on. By biological or identification radioimmunoassay method and found that the above-mentioned diseases in patients with serum, urine and cancer (especially lung oat cell carcinoma) extract of ADH or ADH-like substance increase. SIADH reason may be that the formation of tumors and more similar to the release of ADH peptide material. Due to certain diseases or directly stimulate the hypothalamus to make it due to excessive secretion of ADH. ⑵ drugs: to promote the release of ADH and / or enhance its role in the drug isoproterenol, such as morphine and paracetamol. Antidiuretic mechanism is still unknown but there were cyclophosphamide, amitriptyline (amitriptyline) and fluphenazine and so on. ⑶ the stress caused by a variety of reasons: found in the surgery, trauma and mental stimulation, such as when strong. Under normal conditions, the parasympathetic have inhibitory excited about the role of ADH secretion; stress when the parasympathetic and sympathetic nervous excitement in order to check to the lifting of the parasympathetic inhibition of the secretion of ADH, resulting in increased secretion of ADH easily lead to water intoxication. ⑷ effective to reduce blood volume cycle: the left atrium under the capacity of the endometrium (stretch) receptors, the vagus nerve and hypothalamus links. When too much blood volume expansion in the left atrium, the receptor on by the excitement and stimulation, the incoming impulse along the vagus nerve to reach the hypothalamus, can reduce the release of ADH. Effectively reduce the cycle of blood volume (such as shock, and so on), the left atrium can be spread to the hypothalamus inhibit the impulse to reduce the release of ADH, the number of ADH secretion; at this time, if too much fluid too quickly can lead to water intoxication. ⑸ adrenal insufficiency: adrenal cortex hormones of the hypothalamus inhibit secretion of ADH. Adrenal insufficiency, due to reduced secretion of adrenal cortex hormone, ADH secretion of hypothalamic inhibition will wear off and increased secretion of ADH. If the water can occur at this time a large number of water intoxication. 2. Drainage renal insufficiency in acute and chronic renal failure oliguria, as a result of the drainage of kidney function drop into the water, if unchecked, can cause water retention in the body; severe heart failure or liver cirrhosis, as a result of effective cycle Renal blood flow and blood volume decreased significantly reduce the kidney drainage, is also easy to increase the water load caused by water intoxication. 3. Hypotonic dehydration due to the late extracellular fluid and low permeability, extracellular fluid cells to the transfer. Cells can cause edema, so when they enter a large number of water can cause water intoxication.