[Study on the metabolic changes of hormones regulating water and electrolytes before and after acute water loading in myxedematous patients].

The average plasma AVP in 12 cases of patients with overt myxedema was higher than that of normal controls (n = 5) before water loading, though there was no significant difference (P greater than 0.05). The plasma ANP levels were increased (P less than 0.05). After water loading the average plasma osmolality level of patients was lower, and the mean plasma AVP concentration of patients was not suppressed after loading. A disturbance in water clearance was demonstrated. The mean levels of plasma ANP and aldosterone were not markedly changed in patients before and after loading. These observations coincide with the changes of SIADH. Most of the above blood parameters were improved along with thyroid function in 9 patients who were restored to normal after replacement with desiccated thyroid.