Origin of Diabetes Insipidus and Hypernatremia

There are few studies dealing with the pathophysiology in the central mechanism of water and electrolytes control. The osmoreceptors have been concerned in the region of the supraoptic and paraventricular nuclei (SON, PVN) which are also the area where ADH is formed. Investigations were made on the role of osmoreceptors in ADH-releasing disorder and in experimentally induced diabetes insipidus in the cat and on the involvement of the lateral hypothalamus in these disorders as well as in hypernatremia resulting from disorders of osmoreceptors and the drinking or thirst centers. Daily intake and output, pre and postoperative electrolytes and osmolarity in the serum and urine, plasma ADH and aldosterone were measured in three groups (normal, diabetes insipidus and hypernatremia cats). Experimental diabetes insipidus was induced by the SON lesion on one side, while mild diabetes insipidus with concurrent development of hypernatremia was produced by the SON lesion and an injury to the lateral hypothalamus.