ACTH-independent macronodular adrenal hyperplasia (AIMAH) is an uncommon cause of Cushing's syndrome characterized by bilateral nodular adrenocortical hyperfunction in the presence of suppressed ACTH levels.
AIMAH is a rare condition in which cortisol secretion may be mediated by non-ACTH circulating hormones such as gastric inhibiting polypeptide (leading to food-dependent Cushing's syndrome), vasopressin, catecholamines, luteinizing hormone, serotonin, angiotensin-II or leptin.
A 45-year-old woman with adrenocorticotropin (ACTH)-independent hypercortisolism, diabetes mellitus, and hypertension had undergone left adrenalectomy for ACTH-independent Cushing's syndrome 20 years prior to this presentation.
A naturally occurring ACTH receptor [melanocortin 2 receptor (MC2R)] mutation (F278C) has been identified in a subject with ACTH-independent Cushing's syndrome.
Aberrant expression of glucagon receptors in adrenal glands of a patient with Cushing's syndrome and ACTH-independent macronodular adrenal hyperplasia.
An in vitro experiment using the cultured AIMAH adrenal cells was conducted to investigate cortisol secretion and expression of the V1-AVP receptor, mRNA by RT-PCR.
Because hyper-response of plasma cortisol to vasopressin is documented in some patients with Cushing's syndrome due to adrenal adenoma (CS) or ACTH-independent macronodular adrenocortical hyperplasia (AIMAH), we analyzed the expression of V(1a), V(2), V(3) receptor and AVP mRNA in human adrenal tissues by quantitative competitive RT-PCR or real-time PCRs.
Chronic adrenal stimulation by ACTH in Cushing's disease or GIP in GIP-dependent ACTH-independent macronodular adrenal hyperplasia both lead to the induction of genes implicated in adrenal proliferation and steroidogenesis.
Control of cortisol secretion by the abnormal expression of the gastric inhibitory polypeptide receptor (GIP-R) have been observed in some rare cases of ACTH-independent, food-dependent Cushing's syndrome (FD-ACS) due to adrenal adenoma (AA) or bilateral macronodular hyperplasia (AIMAH).
Corticotropin (ACTH)-independent macronodular adrenal hyperplasia (AIMAH) is a heterogeneous condition in which cortisol secretion may be mediated by gastrointestinal peptide (GIP), vasopressin, catecholamines and other hormones.
Cortisol-producing hyperplasia of the adrenal glands is caused by two distinct syndromes, both of which have been directly or indirectly associated with protein kinase A signaling: (i) primary pigmented nodular adrenocortical disease (PPNAD) (a micronodular form of bilateral adrenal hyperplasia), either isolated (rarely) or in the context of Carney complex, is caused (in most cases) by mutations of the PRKAR1A gene; and (ii) ACTH-independent macronodular adrenal hyperplasia (AIMAH), or massive macronodular adrenal disease (MMAD), has been associated with aberrant (ectopic) expression, and presumably regulation, of various G protein-coupled receptors.