beta-endorphin and Hypopituitarism

Topics: ACTH Syndrome, Ectopic; Anorexia Nervosa; beta-Endorphin; Biomarkers; Depression; Diagnostic Techniques, Endocrine; Humans; Hypopituitarism; Mass Spectrometry; Nelson Syndrome; Pituitary ACTH Hypersecretion; Radioimmunoassay; Radioligand Assay; Reference Values; Specimen Handling

Hypopituitarism can be caused by failure or loss of one or more of the eight identifiable hormones in the anterior lobe of the pituitary gland. The endocrine manifestations of hypopituitarism are related to the type and degree of hormonal deficiency and the stage in life during which the deficiency occurs. In patients with suspected hypopituitarism, the diagnostic approach consists of determining the extent and the cause of the hormonal loss. Specific provocative tests for the diagnosis of hypopituitarism are reviewed in detail in this article.

Topics: Adrenocorticotropic Hormone; Age Factors; beta-Endorphin; beta-Lipotropin; Diagnosis, Differential; Endorphins; Estradiol; Female; Gonadotropins, Pituitary; Growth Hormone; Humans; Hydrocortisone; Hypogonadism; Hypopituitarism; Male; Pituitary Hormones, Anterior; Prolactin; Testosterone; Thyrotropin

Topics: Addison Disease; Adult; beta-Endorphin; Cushing Syndrome; Female; Humans; Hypopituitarism; Infant, Newborn; Male; Nelson Syndrome; Pituitary Function Tests; Pregnancy; Radioimmunoassay; Radioligand Assay; Reference Values

We examined the effect of CRH administration on the response of plasma arginine vasopressin (AVP) induced by an osmotic stimulus in six normal subjects and five patients with hypocorticotropinism without overt diabetes insipidus (four patients with Sheehan's syndrome and one with idiopathic pituitary dwarfism with ACTH deficiency). Hypertonic saline infusion (855 mmol/L saline solutions at a rate of 205 mumol/kg.min for 10 min) increased plasma AVP 5.7-fold (P less than 0.01) in normal subjects and 2.4-fold (P less than 0.05) in the patients. CRH administration significantly augmented the plasma AVP response to the osmotic stimulus in the normal subjects, but not in the patients with hypocorticotropinism. CRH administration alone did not influence plasma AVP. These findings suggest that a central CRH-related mechanism(s) was at least partly involved in the augmentation of AVP release. Based on the relatively low plasma AVP response to the osmotic stimulus in patients and their lower plasma AVP levels and higher plasma osmolality under basal conditions, we suggest that patients with hypocorticotropinism have partial diabetes insipidus, in which impairment of central CRH action might be, at least in part, involved. The response of plasma AVP to the osmotic stimulus was attenuated significantly when the patients were given cortisol. Since basal PRA, plasma aldosterone, plasma osmolality, hematocrit, body weight, mean blood pressure, and heart rate were similar with and without cortisol administration, this effect of cortisol may have been due to central suppression of the AVP response to the osmotic stimulus.

Topics: Adolescent; Adrenal Insufficiency; Adrenocorticotropic Hormone; Adult; Aged; Aldosterone; Arginine Vasopressin; beta-Endorphin; Corticotropin-Releasing Hormone; Diabetes Insipidus; Dwarfism, Pituitary; Glucocorticoids; Growth Hormone; Humans; Hydrocortisone; Hypopituitarism; Male; Prolactin; Reagent Kits, Diagnostic; Saline Solution, Hypertonic

ACTH and lipotropins (beta- and gamma-LPH) are synthesized from a common precursor by the pituitary corticotropic cell. We have measured LPH plasma levels under physiological and pathological conditions and we have compared them with ACTH plasma levels in the same circumstances. Spontaneous variations (nycthemeral rhythm) in LPH, ACTH and cortisol plasma levels were parallel, while responses to Dexamethasone freination test and stress (Insulin induced hypoglycemia) or more specific stimulation (Metopirone, lysine-vasopressin) were parallel and superimposable. LPH levels were always higher than ACTH levels in two pathological circumstances: chronic renal failure and Cushing's syndromes with ectopic ACTH producing tumors. The determination of both ACTH and LPH levels assists the diagnosis of corticotropic insufficiency and etiologic investigation of Cushing's syndrome, after hypercorticolism had been established. Although unable to confirm the presence of corticotropic adenoma in patients with Cushing's disease, or the predict effectiveness of pituitary surgery, these determination bring good arguments for treated Cushing's diseases follow up.

Topics: Adenoma; Adrenocorticotropic Hormone; beta-Endorphin; beta-Lipotropin; Cushing Syndrome; Endorphins; Humans; Hypopituitarism; Kidney Failure, Chronic; Pituitary Neoplasms; Pituitary-Adrenal Function Tests