Pituitary clinical manifestations

Though less frequently sought, endocrine disturbances form an essential part of the clinical picture in malnutrition. Their importance has been emphasized by Samuels (1948), Zubirdn (1949), and by Gillman and Gillman (1951). The similarity between the clinical manifestations of malnutrition and those of altered endocrine function are evidenced by the frequency of serious sexual disturbances, pigmentations of the skin, lowered metabolic rates, gynecomastia, asthenia, hypotension, and other symptoms which could be attributed to dysfunction of the thyroid, the adrenals, the pituitary, or the gonads in undernourished individuals. 

The potent antidiuretic hormone AVP orchestrates the regulation of free water absorption, body fluid osmolality, cell contraction, blood volume, and blood pressure through stimulation of three G-protein-coupled receptor subtypes Vi-vascular types a and b, V2-renal, and V3-pituitary. Increased AVP secretion is the trademark of several pathophysiological disorders, including heart failure, impaired renal function, liver cirrhosis, and SIADH. As a consequence, these patients experience excess water retention or inadequate free-water excretion, which results in the dilution of sodium concentrations, frequently manifesting as clinical hyponatremia (serum sodium concentration <135mmol/L). This electrolyte imbalance increases mortality rates by 60-fold. Selective antagonism of the AVP V2 receptor promotes water... 

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