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Central Diabetes Insipidus
Diabetes insipidus occurs as a result of vasopressin’s (antidiuretic hormone) deficiency. This antidiuretic hormone’s (ADH) deficiency is produced by hypothalamicpituitary disease (central diabetes insipidus) or renal resistance to vasopressin
(nephrotic diabetes insipidus). As a result polydipsia and polyuria occur. Vasopressin
promotes water preservation effects in the kidney primarily by enhancing the permeability of the distal tubular epithelium to water. Vasopressin also causes vasoconstriction at high concentrations. Like aldosterone, vasopressin also plays an
important role in preserving humoral homeostasis as well as cellular and vascular
hydration. The main stimuli of vasopressin secretion are an increase in osmotic
pressure of water in the body (perceived by the osmoreceptors of the hypothalamus)
and volumetric consumption (perceived by vascular baroreceptors). Vasopressin is
synthesized in the hypothalamus, while the main storage site of it is posterior pituitary. The freshly synthesized hormone can be secreted into the circulation if hypothalamic nucleus and neurohypophysis regions are intact. To avoid central diabetes
insipidus, at least 10% of neurosecretory neurons should remain intact. Therefore,
central diabetes insipidus pathology always encompasses the paraventricular and
supraoptic nucleus of the key part of the hypothalamus or pituitary stalk. Central
diabetes insipidus may be partial (insufficient amounts of vasopressin) or complete
(absence of vasopressin). It can also be primary (an obvious reduction in the hypothalamic nuclei of the neurohypophyseal system) or secondary (acquired).
Primary Central Diabetes Insipidus
The genetic abnormality of the vasopressin gene on chromosome 20 is an autosomal
dominant form of primary central diabetes insipidus, but many cases are idiopathic.
Secondary Central Diabetes Insipidus
Central diabetes insipidus may also be secondary (acquired), caused by a variety of
lesions, i.e., pituitary resection, suprasellar or intrasellar tumor (primary or metastatic)
craniocerebral injury (especially basal skull fracture), sexuality, Langerhans cell histiocytosis, granuloma (sarcoidosis or tuberculosis), lymphocytic pituitary inflammation, infection (encephalitis, meningitis), and vascular disease (aneurysm, thrombosis).
Signs and Symptoms
The onset of central diabetes insipidus may be occult or sudden, which may occur
at any age. Symptoms of primary central diabetes insipidus are polyuria and polydipsia. In secondary central diabetes insipidus, there are also signs and symptoms of
1 Physiology of Endocrine System and Related Metabolic Disorders
Central Diabetes Insipidus
Diabetes insipidus occurs as a result of vasopressin’s (antidiuretic hormone) deficiency. This antidiuretic hormone’s (ADH) deficiency is produced by hypothalamicpituitary disease (central diabetes insipidus) or renal resistance to vasopressin
(nephrotic diabetes insipidus). As a result polydipsia and polyuria occur. Vasopressin
promotes water preservation effects in the kidney primarily by enhancing the permeability of the distal tubular epithelium to water. Vasopressin also causes vasoconstriction at high concentrations. Like aldosterone, vasopressin also plays an
important role in preserving humoral homeostasis as well as cellular and vascular
hydration. The main stimuli of vasopressin secretion are an increase in osmotic
pressure of water in the body (perceived by the osmoreceptors of the hypothalamus)
and volumetric consumption (perceived by vascular baroreceptors). Vasopressin is
synthesized in the hypothalamus, while the main storage site of it is posterior pituitary. The freshly synthesized hormone can be secreted into the circulation if hypothalamic nucleus and neurohypophysis regions are intact. To avoid central diabetes
insipidus, at least 10% of neurosecretory neurons should remain intact. Therefore,
central diabetes insipidus pathology always encompasses the paraventricular and
supraoptic nucleus of the key part of the hypothalamus or pituitary stalk. Central
diabetes insipidus may be partial (insufficient amounts of vasopressin) or complete
(absence of vasopressin). It can also be primary (an obvious reduction in the hypothalamic nuclei of the neurohypophyseal system) or secondary (acquired).
Primary Central Diabetes Insipidus
The genetic abnormality of the vasopressin gene on chromosome 20 is an autosomal
dominant form of primary central diabetes insipidus, but many cases are idiopathic.
Secondary Central Diabetes Insipidus
Central diabetes insipidus may also be secondary (acquired), caused by a variety of
lesions, i.e., pituitary resection, suprasellar or intrasellar tumor (primary or metastatic)
craniocerebral injury (especially basal skull fracture), sexuality, Langerhans cell histiocytosis, granuloma (sarcoidosis or tuberculosis), lymphocytic pituitary inflammation, infection (encephalitis, meningitis), and vascular disease (aneurysm, thrombosis).
Signs and Symptoms
The onset of central diabetes insipidus may be occult or sudden, which may occur
at any age. Symptoms of primary central diabetes insipidus are polyuria and polydipsia. In secondary central diabetes insipidus, there are also signs and symptoms of
1 Physiology of Endocrine System and Related Metabolic Disorders