adrenomedullin and Adrenal-Insufficiency

Adrenomedullin (AM) is a recently discovered potent vasodilatory peptide, originally isolated in extracts of human pheochromocytoma, with activities including maintenance of cardiovascular and renal homeostasis through vasodilatation, diuresis and natriuresis. Human AM consists of 52 amino acids with a 6-member ring structure linked by a disulfide bond and amidated COOH terminal, which belongs to calcitonin gene-related peptide (CGRP) and amylin. The main sites of AM production are the lungs, vascular tissues (both endothelial and smooth muscle cells), heart, kidney, adrenal glands, pancreatic islets, placenta, anterior pituitary gland and gastrointestinal neuroendocrine system. Intravenous injection of AM increases blood flow predominantly in the tissues with the highest AM expression, suggesting that AM functions primarily as a paracrine/autocrine hormone, but it is also important as circulating hormone. The objective of this review is to analyze the evidence that AM may play a role in some endocrine disorders.

Topics: Adrenal Insufficiency; Adrenocorticotropic Hormone; Adrenomedullin; Amino Acid Sequence; Cushing Syndrome; Diabetes Mellitus; Endocrine System Diseases; Female; Humans; Hyperaldosteronism; Hyperparathyroidism; Hyperthyroidism; Insulinoma; Male; Menstrual Cycle; Molecular Sequence Data; Molecular Structure; Paraneoplastic Endocrine Syndromes; Peptides; Pheochromocytoma; Pregnancy

We asked whether plasma concentrations of endothelin-1 (ET-1) or adrenomedullin (ADM) are altered by different activity states of the renin-angiotensin-aldosterone system (RAAS). Levels of ET-1 and ADM were studied in patients with primary aldosteronism (n = 15), essential hypertension (n = 15), and adrenal insufficiency (n = 7). Effects of fludrocortisone, dexamethasone, or spironolactone treatment on ET-1 and ADM levels were also analyzed. Plasma ET-1 and ADM concentrations did not differ significantly between the patient groups. After fludrocortisone, dexamethasone, or spironolactone treatment, both ET-1 and ADM did not change significantly. The data support the hypothesis that the RAAS is not directly linked with the ET-1/ADM system.

Topics: Adrenal Insufficiency; Adrenomedullin; Adult; Anti-Inflammatory Agents; Biomarkers; Dexamethasone; Diuretics; Endothelin-1; Female; Fludrocortisone; Humans; Hyperaldosteronism; Hypertension; Male; Middle Aged; Renin-Angiotensin System; Spironolactone

Adrenomedullin (AM) is a recently purified hypotensive peptide and its encoding gene has been sequenced from a human pheochromocytoma. High levels of AM have been shown in Addison's disease (AD). X-linked adrenoleukodystrophy/adrenomyeloneuropathy (ALD/AMN) is a peculiar adrenal insufficiency due to an accumulation of very-long chain fatty acid in adrenal cells and it is very often associated with a devastating demyelination of the central nervous system.. We studied the AM plasma levels of 22 patients with ALD/AMN (18 with hypoadrenalism, ALDa, and 4 with normal adrenal function, ALDb) and compared them with 18 males with classical AD and 16 normal male subjects. All patients with hyposurrenalism were studied before treatment with hydrocortisone.. Both patients with ALD/AMN and AD showed increased levels of AM and all of them showed a significant difference from the control group (p < 0.0001). The plasma renin activity was higher in all patient groups than in the control group (p <0.001 ALDa, ALDb and AD vs. control group). The aldosterone levels were higher in ALDa and ALDb groups than AD (ALDa vs. AD p < 0.01; ALDb vs. control group p < 0.05; AD vs. controls p < 0.01). ACTH plasma levels were higher in ALDa and AD than ALDb and the control group (ALDa vs. AD not significant while ALDa and AD vs. control p <0.0001).. Our data indicate that plasma AM levels in ALDa, ALDb and AD are higher than controls. These results were previously described in untreated AD. While classical AD patients show complete adrenal insufficiency (both mineralocorticoid and glucocorticoid defects), ALD/AMN patients show a less compromised glomerular function, indicating that AM is not completely correlated with mineralocorticoid insufficiency, and that the exact mechanism responsible for the increased AM levels in ALD/AMN is still unknown.

Topics: Addison Disease; Adolescent; Adrenal Insufficiency; Adrenoleukodystrophy; Adrenomedullin; Adult; Case-Control Studies; Child; Humans; Male; Middle Aged; Peptides