Disease relevance of Zona Fasciculata

• Zona glomerulosa possesses both ETA and ETB, whereas zona fasciculata/reticularis is almost exclusively provided with ETB [1].
• Continuous adrenocorticotropin administration in hypopituitarism produces asynchronous increases of deoxycorticosterone and 11-deoxycortisol relative to other reduced zona fasciculata steroids [2].
• In glucocorticoid-remediable aldosteronism (GRA) a chimeric gene has been described with the activity of aldosterone synthase, but the promoter of 11 beta-hydroxylase leading to ectopic expression of aldosterone synthase activity in the zona fasciculata [3].
• These results suggest that, in bovine adrenal fasciculata cells, A-II receptors are coupled to the phosphoinositide pathway through pertussis toxin sensitive and insensitive Gp protein(s) [4].
• In further trials, daily im injections of sodium ascorbate with Dl-alpha tocopherol, desferrioxamine and oral butylated-hydroxyanisole prevented adrenal damage and induced adrenocortical hypertrophy of the zona fasciculata [5].

High impact information on Zona Fasciculata

• These abnormalities could result from ectopic expression of aldosterone synthase, which is normally expressed only in adrenal glomerulosa, in the adrenal fasciculata [6].
• Fluorescent immunocytochemical staining of rat adrenal zona fasciculata showed cyclic AMP largely confined to cytoplasmic elements with little fluorescence contained in nuclei [7].
• The zona fasciculata is hyperplastic and makes aldosterone and "hybrid steroids" 18-oxocortisol and 18-hydroxycortisol in excess, in response to ACTH but not to angiotensin II [8].
• Immunoreactivity to ACS4 was detected in the zona fasciculata and reticularis of adrenal gland, in the corpus luteum and stromal luteinized cells in ovary, and in the Leydig cells of testis [9].
• A related isozyme in the zona fasciculata, CYP11B1, is required for cortisol synthesis; this isozyme, which is normally expressed at much higher levels than CYP11B2, only has 11 beta-hydroxylase activity [10].

Chemical compound and disease context of Zona Fasciculata

• The prolonged administration of the hypocholesterolaemic drug 4-APP induced morphological changes in rat zona fasciculata cells (AER hypertrophy, peroxisome proliferation and lipid droplet depletion), enabling them to synthesise their own cholesterol and to maintain an adequate level of corticosterone output [11].
• In the outer zona fasciculata estradiol leads to a feminization of cell pattern in males with increase of cell sizes and partly also development of a female liposome pattern [12].
• Beclomethasone dipropionate given intratracheally at daily dose levels of 0.05; 0.1 and 0.5 mg/kg body weight lead to a dose dependent adrenal suppression on the basis of plasma cortisol concentration, eosinophil counts after ACTH stimulation and size of zona fasciculata and reticularis [13].
• Long-term alpha-MSH treatment induced a notable hypertrophy of zona glomerulosa cells and a further rise in the blood concentration of aldosterone. alpha-MSH did not affect zona fasciculata morphology and corticosterone plasma level [14].
• RESULTS: Carbimazole-induced hypothyroidism causes the adrenal atrophy in the adrenals of 10 days' prenatally treated albino rats by decreasing the total width of cortex and its zones especially zona fasciculata [15].

Biological context of Zona Fasciculata

• Bovine adrenal zona fasciculata (AZF) cells express a noninactivating K+ current (IAC) that sets the resting membrane potential and may mediate depolarization-dependent cortisol secretion [16].
• Expression of the zone-specific steroidogenic enzymes, cytochrome P450 aldosterone synthase (P450aldo), and P450 11beta hydroxylase (P45011beta), produced by the zona glomerulosa and zona fasciculata/reticularis, respectively, can be used to define the adrenal cortical cell phenotype of these two zones [17].
• The combined adrenal weight and adrenocortical thickness were greater (P < 0.001), and cell density was lower (P < 0.01), in the zona fasciculata of adrenals from the metyrapone-infused group [18].
• We have shown previously that angiotensin-II (A-II) controls proto-oncogene (c-fos, jun-B and c-jun) mRNA accumulation in bovine adrenal fasciculata cells (BAC) [19].
• We have examined Ang II-mediated signal transduction in homogeneous cellular sub-populations derived from either the zona glomerulosa (GLOM) or the zona fasciculata (FASC) [20].

Anatomical context of Zona Fasciculata

• The CYP11B1 gene, which encodes steroid 11 beta-monooxygenase, which is responsible for the synthesis of cortisol and corticosterone, the major glucocorticoids in mammals, is expressed specifically in the zona fasciculata of the adrenal cortex [21].
• Initially found in immune cells, IL-18 mRNA is detectable in several tissues including the cells of the zona reticularis and the zona fasciculata of the adrenal cortex, where its levels are elevated by acute stress or adrenocorticotropic hormone treatment [22].
• In the present study, the direct effect of certain components of the immune system on steroid output by rat adrenal fasciculata cells was tested [23].
• The role of CXCL10 in the adrenal gland was also evaluated in vitro in human zona fasciculata cells (hZFC) [24].
• The basal activity of the Na+/K+ pump was much higher in glomerulosa cells than in adrenal fasciculata cells or hepatocytes, as judged by the ouabain-sensitive uptake of 86Rb [25].

Associations of Zona Fasciculata with chemical compounds

• Gonadal luteinizing hormone receptors and adenylate cyclase: transfer of functional ovarian luteinizing hormone receptors to adrenal fasciculata cells [26].
• Qualitatively and quantitatively similar results were obtained for corticosterone production in adrenal fasciculata cells [27].
• One of these (CYP11B1) encodes P450c11 beta, which is the steroid 11 beta-hydroxylase found solely in the adrenal zona fasciculata/reticularis, and is responsible for the conversion of 11-deoxycorticosterone to corticosterone [28].
• The steroid 11 beta-hydroxylase (P450c11) enzyme is responsible for the conversion of 11-deoxycortisol to cortisol in the zona fasciculata of the adrenal cortex [29].
• After administration of metoclopramide (an antagonist of dopamine-2 receptor), the increment of plasma aldosterone correlated inversely with the percentage of zona fasciculata cells of APA [30].

Gene context of Zona Fasciculata

• Inhibitory adenylyl cyclase 3 antibodies interfered with ACTH action only in the zona fasciculata [31].
• In adrenal fasciculata cells, the glucocorticoid secretion is under the control of ACTH, which binds specifically MC2-R, the only functional melanocortin receptor described in these cells to date [32].
• TGF-alpha expression was observed in the cells with increased steroidogenesis, including compact tumor cells and zona fasciculata cells with lipid depletion, but did not necessarily correlate with production sites of any specific steroid hormone [33].
• Raised plasma and urinary levels of 11-deoxycortisol suggest that there is relative inefficiency of 11beta-hydroxylation in the zona fasciculata; the P450 enzyme responsible for this step is encoded by the gene CYP11B1, which is highly homologous with and adjacent to CYP11B2 [34].
• The levels of expression of each isoform were similar between the two adrenocortical zones, except for adenylyl cyclase 5/6, which had a lower level of expression in the zona fasciculata [31].

Analytical, diagnostic and therapeutic context of Zona Fasciculata

• To determine the subcellular location of StAR in steroidogenic cells, ultrastructural immunocytochemistry was performed in adrenal zona fasciculata cells using the protein A-gold technique [35].
• In situ hybridization localized OAT1 in the outer zona fasciculata, oatp3 in the zona glomerulosa, and oatp1 and oatp2 in the inner zona fasciculata and outer zona reticularis [36].
• Following autoradiography or immunohistochemical detection of the digoxigenin cytochrome P45011B1 mRNA was clearly localized in the zona fasciculata/reticularis of non-tumour portion of an human adrenal with an APA [37].
• Ovariectomy prolonged the S phase in the zona fasciculata and shortened this time in the reticular zone, an effect reversed by estradiol [38].
• Our studies, using the in situ isolated perfused rat adrenal preparation, have shown that zona fasciculata function and corticosterone secretion are closely related to vascular events, with an increase in perfusion medium flow rate causing an increase in corticosterone secretion, in the absence of any known stimulant [39].

References