Pathophysiologic and pharmacologic alterations in the release and action of ADH.

The physiologic factors involved in vaseopressin (ADH) release and action are reviewed with emphasis on the interaction between osmotic and volume stimuli to the discharge of ADH. Abnormalities in reception of stimuli to ADH release, and in the impaired synthesis and release of ADH, are reviewed in relation to the causes of diabetes insipidus, and information on the biochemical changes which have been described in patients with nephrogenic diabetes insipidus is also discussed. We summarize the pathologic lesions and associated diseases found in 54 of our patients with diabetes insipidus. Criteria for establishing the diagnosis of diabetes insipdus are reviewed with emphasis on the dehydration test, including the importance of measuring plasma osmolality at the conclusion of water deprivation. Treatment of diabetes insipidus is briefly discussed with emphasis on the use of DDAVP and oral agents. The syndrome of inappropriate ADH secretion (SIADH) is reviewed including our experience with 39 patients. The differential diagnosis of SIADH, including the value of water loading and the measurement of ADH levels, is discussed. We comment on treatment of these patients including the use of investigational drugs. Lastly, we review the pharmacologic features and clinical relevance of some drugs which alter the release and action of ADH.