Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ADRENAL CORTEX”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources

131I-19-iodocholesterol scintigraphy of the adrenal cortex.

131-I-19-iodocholesterol scintigraphy of the adrenal cortex has been carried out in 26 patients. In 4 patients with normal adrenocortical function the tracer was equally accumulated on the two sides. In 7 patients with untreated Cushing's syndrome, bilateral uptake was found in 4 patients with bilateral hyperplasia whereas unilateral visualization was obtained in three cases of cortisol producing adenomas. The side localization was confirmed at operation. Eight patients had been operated for Cushings syndrome prior to the scintigraphy. Remnant adrenocortical tissue with negligible or subnormal function (4 patients) could not be visualized. Normo- or hyperfunctioning remnant tissue was visualized in 3 patients. One patient had recurrent hypercorticism due to metastases from a previously removed adrenocortical carcinoma; a single pelvic accumulation was seen, whereas several metastases in the abdomen and thorax were not visualized. Four patients with aldosteronism were investigated. Three had primary aldosteronism due to an adrenocortical adenoma. In two of these, the site of the adrenal lesion was localized pre-operatively. In the third patient, equal bilateral accumulation of iodocholesterol was seen even after suppression with dexamethasone. At operation a small tumour was found. In 1 patient with indeterminate aldosteronism both glands were visualized and at a second examination the uptake was equally suppressed by dexamethasone.

Adrenal Cortex↗

[Prolactin level in congenital adrenal cortex dysfunction].

Study of prolactin secretion in patients with congenital adrenal cortex dysfunction demonstrated that the majority of untreated patients displayed elevated blood prolactin content. Blood prolactin level fell after treatment with glucocorticosteroids. Blood prolactin level was elevated, irrespective of normal or increased 24-hour 17-CS excretion in patients with congenital adrenal gland dysfunction treated with glucocorticosteroids and with persistent disturbances of ovarian function.

17-Ketosteroids↗

The activation of adrenal cortex mitochondrial malic enzyme by Ca2+ and Mg2+.

Adrenal cortex mitochondria prepared by a standard method do not exhibit malic enzyme activity. Addition of physiological concentrations of Ca2+ and Mg2+ enables these mitochondria to reduce added NADP+ by malate to form free NADPH. Half-maximum activation of the mitochondrial malic enzyme requires 0.3 mM Ca2+ and 1 mM Mg2+. Solubilized mitochondrial malic enzymes is independent of Ca2+ and has a K M of 0.2 mM for Mg2+. The Ca2+ effect is dependent on an initial period of active Ca2+ uptake which also causes other changes in respiratory properties similar to those observed with mitochondria from other tissues. After Ca2+ accumulation has taken place, free Ca2+, but not additional accumulation, is still required for malic enzyme activity. The requirement for Mg2+ can be met by Mn2+ (1 mM). This concentration of Mn2+ alone yielded only a slight activation of mitochondrial malic enzyme while higher concentrations of Mn2+ alone gave good activation of the mitochondrial malic enzy.e The NADPH generated by the Ca2+-Mg2+ activated malic enzyme effectively supports the 11beta-hydroxylation of deoxycorticosterone, whereas in the presence of malate, or malate plus Mg2+ but absence of Ca2+, the energy linked transhydrogenase supplies all the required NADPH. The activated malic enzyme appears to be more efficient than transhydrogenase in generating NADPH to support 11beta-hydroxylation. Cyanide and azide have been found to inhibit solubilized mitochondrial malic enzyme.

Adrenal Cortex↗

[The functional activity of rat fetus adrenal cortex in monolayer tissue culture].

A study was made of the functional activity of the adrenal cortex in 15 1/2-, 18 1/2-, and 21 1/2-day rat fetuses and neonates. Adrenal tissue was incubated after its preliminary trypsinization at 37 degrees C for over 2 weeks with and without ACTH addition into the culture medium, in the amount of 0.1 U/ml. The corticosterone level was determined in the culture medium fluorimetrically. The activity of 3 beta-oxysteroid dehydrogenase was determined histochemically. Corticosterone was revealed in the culture medium. The activity of 3 beta-oxysteroid dehydrogenase was found in the cells of the cultivated adrenal glands. Addition of ACTH into the culture medium considerably increased the corticosterone level and elevated the activity of 3 beta-oxysteroid dehydrogenase. It can be considered on the basis of the aforesaid that cells of the primary culture of the adrenal cortex of rat fetuses aged 15 1/2-, 18 1/2-, and 21 1/2-days and of neonates could form, in the process of incubation, corticosterone from the endogenous substrates in the course of 11, 16, 8 and 13 cultivation days, respectively. The presence of ACTH in the culture medium for the adrenal glands of rat fetuses (of all the gestation periods under study) and of neonates intensified the steroidogenesis.

Adrenal Cortex↗

[Effect of experimentally induced hyperthyroidism on zona glomerulosa from adrenal cortex of the rat (author's transl)].

By histochemical and histometrical methods the the effect of l-triiodothyronine on the zona glomerulosa from rat adrenal cortex was investigated. Glucose-6-phosphatedehydrogenase and 3-beta-OH-steroiddehydrogenase activities were determined in slices of adrenal cortex. No increase in activities of these enzymes was observed after treatment with l-triiodothyronine. In contrast, histometrical studies showed a significant enlargement of nuclei in the zona glomerulosa as well as in the zona fasciculata. This observation suggests enhanced secretory activity of both zones of the adrenal cortex of the rat.

Adrenal Cortex↗

Proliferation and apoptosis in the guinea pig adrenal cortex during postnatal development.

The aim of the study was to determine the relation between involution of the FZ and the proliferation and apoptosis of the adrenal cortex cells. The study was carried out with adrenal glands from guinea pigs aged 1, 3, 9, 14, 21, 35 and 90 days. Paraffin slices were stained with Mayer haematoxylin and eosin and with acid fuchsin. For the immunohistochemical reaction the Anti -PCNA Clone PC10 (Dako) was used. Apoptosis evaluation was performed with use of the TUNEL method (Roche). The results support the theory of involution of the FZ cells realised mainly by way of apoptosis. Analysis of the distribution and number of PCNA-positive cells in the adrenal cortex on subsequent days of PD may also back up the migration theory of renewal of the adrenal cortex cells.

Adrenal Cortex↗

Innervation of the adrenal cortex, its physiological relevance, with primary focus on the noradrenergic transmission.

The current knowledge of the catecholaminergic innervation of the mammalian adrenal cortex is summarized, and macro- and microscopic neuromorphology, including the central nervous system connections of the adrenal cortex, is briefly discussed. Morphological and functional data on the catecholaminergic (i.e., noradrenergic) innervation of the adrenal cortex are reviewed. Experimental data suggest that in addition to the regulation of adrenal blood flow, the noradrenergic innervation has a primary influence on zona glomerulosa cells possibly via beta 1 adrenergic and dopaminergic receptors (DA2 subtype via inhibiting T-type Ca2+ channels) It is concluded that the local, modulatory effect of noradrenergic nerve fibres, terminating in the close vicinity of the zona glomerulosa cells, on the systemic renin-angiotensin-aldosterone and other peptide cascade may be influenced by neuropeptides, particularly neuropeptide Y and vasoactive intestinal peptide.

APUD Cells↗

Laminin isoforms in fetal and adult human adrenal cortex.

Laminin has been proposed to influence the function of human adrenal cortex. We have studied the distribution of laminin (Ln) chains using immunofluorescence in human fetal and adult adrenal cortex. In the fetal gland Ln alpha2- and alpha5-chains were weakly expressed in the definitive zone, whereas Ln alpha4-, beta1-, and gamma1-chains occurred around vessels. In the adult gland, Ln alpha2-, alpha5-, and gamma1-chains were found in epithelial basement membranes (BM) in all cortical zones, Ln alpha4-chain in vessels, Ln beta1-chain in outer zone, and Ln beta2-chain in the two inner zones of the cortex, respectively. Among the integrins in adult gland, integrin alpha(3)-subunit was confined to basal surfaces of cortical cells, alpha(6) to vessels, alpha(1) to the stroma, and alpha(2) diffusely to epithelial cells. Lutheran glycoprotein and dystroglycan occurred in the fetal gland diffusely in the definitive zone and throughout the epithelium in the adult. The isoform composition of BM of the adult adrenal gland is distinct, with Ln-2 and -10 in BM of the outer zone and Ln-4 and -11 in BM of the two inner zones. The results suggest that integrin alpha(3)beta(1) and Lutheran are candidate receptors for Ln-10 and -11, whereas dystroglycan probably binds Ln-2 and -4.

Adrenal Cortex↗

Effect of paraquat on cytochrome P-450-dependent lipid peroxidation in bovine adrenal cortex mitochondria.

We have investigated the effect of paraquat (methyl viologen) on lipid peroxidation in bovine adrenal cortex mitochondria. Incubation of a buffered aerobic mixture of mitochondria in the presence of Fe2+ or NADPH resulted in the formation of lipid peroxides whose accumulation could be followed at 532 nm as malondialdehyde. Fe2+ stimulates lipid peroxidation in normal mitochondria and those in which enzymes have been inactivated with heat. In contrast, NADPH has a stimulatory effect only in normal mitochondria, but not in heat-treated mitochondria. These results indicate that NADPH-dependent lipid peroxidation is an enzymatic process. Paraquat strongly inhibits this enzymatic lipid peroxidation, but has no effect on the non-enzymatic Fe2+-dependent process. The chemiluminescence that accompanies the NADPH-dependent lipid peroxidation is also markedly decreased in the presence of paraquat. Superoxide dismutase, which removes superoxide anion efficiently, does not inhibit malondialdehyde production. The mechanism of the inhibition of the lipid peroxidation by paraquat has been examined. Paraquat has no effect on NADPH-2,6-dichlorophenolindophenol reductase and on NADPH-cytochrome c reductase activities in bovine adrenal cortex mitochondria. However, paraquat strongly inhibits the NADPH-dependent reduction of cytochrome P-450. These results suggest that the inhibitory effect of paraquat on NADPH-dependent lipid peroxidation in adrenal cortex mitochondria is due to a decrease in the level of reduced cytochrome P-450 probably by diverting electrons from cytochrome P-450. Cytochrome c, which can compete with P-450 for available electrons from adrenodoxin, like paraquat had an inhibitory effect on NADPH-dependent lipid peroxidation. Lipid peroxidation was also strongly inhibited by steroid hydroxylase inhibitors, e.g., amphenone B, aminoglutethimide and metyrapone.

Adrenal Cortex↗

[131-I cholesterol (19-C) in the functional and localization diagnosis of adrenal cortex disorders].

Results are reported of quantitative adrenal scintigraphy with 131I-cholesterol in 8 patients with normal adrenal function before and after ACTH-stimulation and cortisol-suppression respectively, in one case with an adrenal metastasis from a pulmonary cancer, in two cases with Cushing's disease and in 7 cases with Conn's disease. In normal cases and in patients with M. Cushing a diagnosis of adrenal cortical function is possible with this method but can usually be replaced by more specific biochemical studies of serum and urine. The scintigraphic method is in addition of value in localization studies and can in unequivocal cases replace the selective adrenal phlebography. In patients with M. Conn increased uptake values (bilateral adrenal cortex hyperplasia) as well as reduced or non-detectable uptakes were observed, one of these cases suffering from a cortex carcinoma with M. Conn.

Adrenal Cortex Function Tests↗

Catecholaminergic innervation of the rat adrenal cortex.

The zona glomerulosa of the rat adrenal gland is innervated by catecholaminergic nerves. Using histofluorescence techniques, we observed catecholaminergic plexuses surrounding adrenal capsular and subcapsular blood vessels. Individual varicose nerve fibers that branched off these plexuses were distributed among adrenal glomerulosa cells. This innervation was permanently eliminated after neonatal sympathectomy with guanethidine or 6-hydroxydopamine, but was not affected by ligation of the splanchnic nerve or extirpation of the suprarenal ganglion. At the ultrastructural level, axonal varicosities were commonly observed in close proximity to glomerulosa cells and blood vessels. Nerve fibers and varicosities were found to contain small (30-60 nm) clear vesicles as well as large (60-110 nm) and small (30-60 nm) dense-cored vesicles. In tissue fixed for the dichromate reaction with or without pretreatment with the false transmitter 5-hydroxydopamine, many nerve terminals contained numerous small dense-cored vesicles which are thought to contain catecholamines. These results establish the anatomical substrate for the catecholaminergic innervation of the rat adrenal cortex.

Adrenal Cortex↗

Immunofluorescence microscopic evaluation of the intermediate filament expression of the adrenal cortex and medulla and their tumors.

Normal adrenal glands (10 specimens) and adrenal gland tumors (58 cases) were immunohistochemically evaluated for different types of intermediate filament (IF) proteins. Some of the normal cortical cells showed cytokeratin positivity, and no positivity was seen for epidermal keratin or other types of IF. In the adrenal medulla, neurofilament positivity was seen in nerve axons, some ganglion cells, and chromaffin cells; and cytokeratin-positive cells could not be detected. Only the vascular and connective tissue elements showed vimentin positivity in both cortical and medullary areas. In half of the cortical carcinomas (13/25), cytokeratin-positive tumor cells were found. Furthermore, vimentin-positive tumor cells were present in 10 of 25 cases, in some of them together with cytokeratin-positive cells. Thus, the results show heterogeneity among the adrenal cortical carcinomas. Interestingly, many benign adrenal cortical tissues and some carcinomas lacked immunoreactivity for all types of IF, suggesting a poorly developed IF system in these tissues. In contrast to adrenal cortical tumors, pheochromocytomas contained neurofilamentlike immunoreactivity. These results reflect the different cellular nature of adrenal cortical and medullary tumors, which apparently can be distinguished from each other with antibodies to intermediate filament proteins.

Adenoma↗

ACTH induces TIMP-1 expression and inhibits collagenase in adrenal cortex cells.

To identify genes that are induced by corticotropin (ACTH) in adrenal cortex cells, we carried out a differential hybridization screening of adrenal cortex cDNA libraries. Some of the clones we identified represented tissue inhibitor of metalloproteinase 1 (TIMP-1) mRNA. We examined ACTH dependence of the expression of TIMP-1 in vitro in cultured bovine adrenocortical cells, and in ACTH-treated rats. Northern blot analysis of total RNA from cells showed that the level of TIMP-1 mRNA increases sharply within 3h after ACTH stimulation. Since TIMP-1 inhibits some cell matrix metalloproteinases (MMPs) of the collagenase type, we examined the effect of ACTH on collagenase activity in bovine adrenocortical cells. Exposure of confluent cultures to ACTH for 24h showed dose-dependent inhibition of collagenase activity. Northern blot analysis of total RNA from rat adrenal zona fasciculata-reticularis and zona glomerulosa showed that in both of these zones TIMP-1 expression was induced within 12h after ACTH injection. Long-term (9 days) treatment with ACTH increased TIMP-1 mRNA levels nearly sixfold in zona fasciculata-reticularis. Overall, our results show that ACTH causes induction of TIMP-1 and suppression of collagenase activity, and suggest that ACTH may modulate the activities of MMPs and hence cell matrix remodeling.

Adrenal Cortex↗

Actions of neuropeptide Y on the rat adrenal cortex.

Although several studies have demonstrated the presence of neuropeptide Y (NPY) in nerves supplying the mammalian adrenal cortex, its function in this tissue remains unclear, with reports of both stimulatory and inhibitory effects on aldosterone secretion apparently depending on the tissue preparation used. In the present study the effects of NPY on rat adrenal capsular tissue were investigated. NPY significantly stimulated aldosterone secretion in a dose-dependent manner, and this effect was abolished by atenolol, a beta1-adrenergic antagonist. NPY also stimulated the release of catecholamines from intact rat adrenal capsular tissue with the same dose-dependent relationship as the stimulation of aldosterone release. These observations suggest that the actions of NPY may be mediated by the local release of catecholamines from chromaffin cells within adrenal capsular tissue, as we have previously described for vasoactive intestinal peptide. The second part of this study concerned the NPY receptor subtype mediating the actions of NPY on the adrenal cortex. It was found that peptide YY stimulated aldosterone release with a comparable potency to NPY, whereas pancreatic polypeptide (PP) was without effect. The Y1 selective NPY analog Leu31Pro34NPY had a greater effect on aldosterone release than the Y2 selective analog NPY18-36. Studies using the specific Y1 receptor antagonist BIBP 3226 showed significant attenuation of the aldosterone response to NPY, but no effect on the response to added norepinephrine. Binding studies carried out using [125I]NPY revealed the presence of a single population of NPY-binding sites with a Kd of 12.25 nmol/liter and a binding capacity of 623 fmol/mg protein. Competition studies revealed displacement of [125I]NPY specific binding by NPY, peptide YY, and Leu31Pro34NPY, but not by other peptides. Messenger RNA analysis revealed the presence of messenger RNA coding for both the Y1 receptor and the Y4 receptor, but not the other subtypes. Taken together these data suggest that the effects of NPY on the rat adrenal cortex are mediated by the Y1 receptor subtype.

Adrenal Cortex↗

Interaction of polyanions with the recognition sites for inositol 1,4,5-trisphosphate in the bovine adrenal cortex.

Inositol 1,4,5-trisphosphate (InsP3) serves as a second messenger for Ca2+ mobilization in a wide variety of cells. InsP3 activates a specific receptor/channel located on an internal Ca2+ store. Because heparin has already been shown to block the action of InsP3, we have looked at the influence of other polyanions (dextran sulfate and polyvinyl sulfate) on the action and metabolism of InsP3 in the bovine adrenal cortex. Polyvinyl sulfate blocked InsP3 binding to adrenal cortex microsomes with a half-maximal efficiency of 250 nM. Scatchard analyses revealed that this effect was not competitive. The Ca2+ releasing activity of InsP3 on the same microsomal preparation was monitored with the fluorescent indicator, fura-2. Polyvinyl sulfate blocked this activity with a half-maximal efficiency of 80 nM. The effect of polyvinyl sulfate could not be overcome by supramaximal doses of InsP3, suggesting a non-competitive inhibitory effect. The activity of InsP3 phosphatase from bovine adrenal cortex microsomes was also studied. Polyvinyl sulfate inhibited the activity of the phosphatase with a half-maximal efficiency of 5 microM. Lineweaver-Burk plots revealed that this effect was not competitive. Polyvinyl sulfate was able to inhibit the activity of InsP3 kinase from bovine adrenal cortex cytosol. The half-maximal dose was 15 nM and the Lineweaver-Burk analysis showed that the inhibition was not competitive. The effect of dextran sulfate 5000 (DS-5000) on these activities was also studied. DS-5000 inhibited in a competitive manner the binding of InsP3 to its receptor (IC50 of 34 microM), the release of Ca2+ induced by InsP3 (IC50 of 6.5 microM) and the activity of InsP3 phosphatase (IC50 of 57 microM).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex↗