Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Desoxycorticosterone (DOC) secretion increases during pregnancy. Administration of adrenocorticotropic hormone (ACTH) to women during the third trimester of pregnancy was noted previously to result in marked sodium retention, while aldosterone excretion declined. Since urinary tetrahydrodesoxycorticosterone increased substantially, sodium retention resulting from ACTH was ascribed to enhanced DOC secretion. Surprisingly, the elevated plasma DOC in late pregnancy failed to respond consistently to ACTH. Effects of ACTH upon total plasma concentrations and free indexes of DOC and cortisol were studied in pregnant women in the third trimester. As a result of ACTH, plasma cortisol and the free cortisol index increased strikingly; the plasma free DOC index rose markedly in those subjects in whom the total plasma DOC level was not altered appreciably and was unchanged or even increased slightly in the few subjects in whom the total DOC level decreased. The results support the proposition that the plasma free DOC fraction is increased because of displacement from corticosteroid-binding globulin by the ACTH-induced increment in cortisol. Resultant elevations of free DOC would not be evident from customary measurements of the total DOC concentration but, nonetheless, could contribute to sodium retention and also would be available for hepatic metabolism.
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PMID:Desoxycorticosterone in normal pregnancy. II. Cortisol-dependent fluctuations in free plasma desoxycorticosterone. 21 56

Implantation of a mammotropic tumor (MtTF4), secreting growth hormone, prolactin, and corticotropin, in female rats of Fischer F344 strain causes hypertension, vasculitis, renal and cardiac hypertrophy, and extensive renal and cardiac lesions. When rats of the same strain were implanted with the MtTF4 tumor but sodium was withheld from the diet, systolic blood pressure rose more slowly but by six weeks reached the same values recorded in the animals implanted with the tumor and allowed to consume sodium ad libitum. In the rats, on sodium deficient diet, however, the vascular damage as well as the renal and cardiac lesions were minimal or absent. Implantation of the tumor caused adrenal cortical dysfunction, and elevated levels of deoxycorticosterone were seen in the peripheral plasma of the rats of all three groups. Nonetheless, plasma deoxycorticosterone was significantly lower in rats on a sodium deficient diet as compared with those having sodium added to the diet. Light microscopic and ultrastructural studies of the adrenal glands revealed that the lack of dietary sodium largely prevented the extensive damage of the zona fasciculata cells usually seen in the tumor-bearing rats, consuming sodium ad libitum. Both hypertensive MtT tumor-bearing animals and normotensive controls on a sodium deficient diet had a conspicuous increase of renal content of renin. It is evident that hypertension may be produced in rats bearing the MtTF4 tumor even in the virtual absence of dietary sodium. It does not appear that the hypersecretion of renal renin sustains the hypertension in these rats, since high levels of this substance were seen in the kidney of normotensive controls on the same sodium deficient diet. Elevated levels of plasma DOC may possibly explain the hypertension. In addition, it is likely that the animals may also have elevated levels of glucocorticoids.
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PMID:Deveolpment of hypertension in rats maintained on a sodium deficient diet and bearing a mammotropic tumor (MtTF4). 81 73

The effects of adrenocorticotropic hormone (ACTH), cyclic AMP (cAMP), NADPH, Krebs cycle intermediates (KCl), and metyrapone on the two key mitochondrial reactions in the biosynthesis of glucocorticoids--11 beta-hydroxylation and cholesterol cleavage--were studied in preparations from the adrenal glands of stranded whales (Kogia breviceps and Mesoplodon europaeus) and some terrestrial mammals. ACTH (30 pM) and cAMP (1.0 mM) enhanced the 11 beta-hydroxylation of [11-3H]deoxycorticosterone ([3H]DOC) in monolayer cultures of whale adrenal cells during a 4-hr incubation period. Mitochondria from whale and beef adrenals responded in a similar dose-related fashion to NADPH generated by the addition of increasing amounts of NADP (0-0.6 mM) to the in vitro system: at each level of NADPH, 11 beta-hydroxylation of [14C]DOC was several-fold greater than the cleavage of [14C]cholesterol. Metyrapone interfered in a dose-related manner with both the 11 beta-hydroxylation of [14C]DOC and the cleavage of [14C]cholesterol by mitochondria from whale and beef adrenals; inhibition of 11 beta-hydroxylation exceeded 60% at 0.1 mM metyrapone and was virtually complete at 1.0 mM in both species, while inhibition of [14C]cholesterol cleavage averaged 25% at 0.1 mM metyrapone and 50% at 1.0 mM. The effect of exogenous NADPH in supporting the 11 beta-hydroxylation of [14C]DOC could be maintained in beef and rat adrenal mitochondria to the extent of 70-100% by substitution with any of the KCl. This phenomenon was not found in similar whale studies where the KCl were all ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The adrenal gland of stranded whales (Kogia breviceps and Mesoplodon europaeus): in vitro modulation of mitochondrial steroid enzyme activities. 282 52

offlated hypoaldosteronism with or without hyperkalemia in patients with diabetes mellitus has been shown to exist occasionally without hyporeninemia. To assess in detail the adrenal function in this disorder, the responses of plasma aldosterone (PA) and its precursor steroids to angiotensin II (AII) infusion and adrenocorticotropic hormone (ACTH) injection were studied in seven patients with asymptomatic normoreninemic hypoaldosteronism (ANH) and 11 age-matched normal subjects. The ANH diabetic patients had, by definition, a low PA level after furosemide (80 mg orally) plus upright posture (4 hours) stimulation, low PA and high plasma renin activity (PRA) increases after the stimulation (a low delta PA/delta PRA ratio), and normokalemia. Plasma inactive renin and the inactive renin/total renin ration were similar in the ANH diabetic patients and in the normal subjects. Under the pre-AII condition, plasma DOC and corticosterone levels tended to be low, and the plasma 18-OHB and PA levels were low in the ANH diabetic patients compared with the normal subjects. The ratio of plasma 18-OHB to PA was similar in the two groups. All infusion produced no increases in plasma 18-OHB and PA in the ANH diabetic patients, whereas the infusion caused dose-dependent increases in these steroids in the normal subjects. Plasma DOC and corticosterone levels remained unchanged during AII infusion in the two groups. ACTH injection produced appropriate PA increases relative to the basal PA in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Unresponsiveness of plasma mineralocorticoids to angiotensin II in diabetic patients with asymptomatic normoreninemic hypoaldosteronism. 298 80

Cholesterol, pregnenolone, progesterone, 11-deoxycorticosterone (11-DOC) and corticosterone were quantitated in subcellular fractions isolated from in vivo adrenocorticotropin (ACTH)-stimulated rat adrenal zona fasciculata/reticularis. Six adrenal subcellular fractions separated by discontinuous sucrose gradient centrifugation (lipid, 0.125 M sucrose, cytosolic, microsomal, mitochondrial and nuclear) were extracted with alkaline ether/ethanol and assayed by high pressure liquid chromatography (HPLC). Lipid fractions contained the major cholesterol stores, while most pregnenolone and progesterone was found in lipid, microsomal and mitochondrial fractions. The 0.125 M sucrose and cytosol fractions together contained approximately 75% of the total 11-DOC and corticosterone. The five steroids were only present in small amounts in organelle fractions containing steroidogenic enzymes. Homogenate and lipid fraction cholesterol decreased between 10 and 15 min and again 30 min after ACTH injection. In the homogenate, lipid, microsomal and mitochondrial fractions, pregnenolone and progesterone were increased after ACTH injection; peak pregnenolone and progesterone concentrations were often measured in adrenal gland sucrose, cytosolic, microsomal and mitochondrial fractions 15 to 20 min after rats were injected with ACTH. Although ACTH increased 11-DOC and corticosterone in all but the mitochondrial and nuclear fractions, the sucrose, cytosolic and microsomal 11-DOC, and cytosolic corticosterone increased most dramatically. In many fractions, peak 11-DOC and corticosterone concentrations were most often observed between the 10 and 15 min periods and again at 30 min.
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PMID:Extraction of corticosterone from cell homogenates and subcellular fractions of the rat adrenal cortex. III. ACTH-induced temporal subcellular redistributions of steroid precursors to corticosterone. 301 51

The work is devoted to a study of the hypophysis control of the adrenal cortex hormone--18-hydroxy-11-deoxycorticosterone (18-HO-DOC) secretion; these investigations were performed on 136 mongrel female rats, weighing 130-140 g. The regulating role of the hypophysis on the 18-HO-DOC secretion was ascertained on the hypophysectomized animals (pseudohypophysectomized animals served as control) and intact rats to which ACTH was administered (physiological saline was injected to control animals). The rate of secretion, specific rate of secretion, and the secretion content in the blood and in the arenal efferent and the peripheral vessels were determined by thin-layer chromatography and competitive protein binding. The data obtained led to the conclusion that both corticosterone and 18-HO-DOC were regulated by the hypophysis. Under the effect of stress there apparently occurred selective regulating action of ACTH on 18-HO-DOC and corticosterone secretion indicating that the expediency of elevation of one or another steroid secretion was determined by the character of stress reaction, the blood adrenocorticotropin and corticosteroid level.
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PMID:[Role of the anterior pituitary gland in the regulation of 18-hydroxydesoxycorticosterone by the adrenal cortex]. 625 46

Immunoreactive ACTH (ir-ACTH) and immunoreactive beta-endorphin (ir-betaEP) were determined in plasma, anterior pituitary, neuro-intermediate lobe, and hypothalamus of sham-adrenalectomized rats, and adrenalectomized rats given six daily injections of vehicle (oil), dexamethasone, 9alpha-fluorocortisol or deoxycorticosterone. 6 d after adrenalectomy, anterior pituitary ir-ACTH and ir-betaEP were double, and plasma levels approximately fivefold those in controls. Adrenalectomy did not alter hypothalamic levels of either peptide, or ir-betaEP in neuro-intermediate lobe, in which tissue ir-ACTH was below detection limit at routine dilutions. Dexamethasone (0.2-200 mug/d) concurrently suppressed plasma ir-ACTH and ir-betaEP, with a near maximal effect at 20 mug, and a half-maximal effect between 2 and 6 mug; similar dose-response characteristics were found for thymolysis. Step-wise increases in anterior pituitary content of both peptides were found, with no change in hypothalamic levels of either peptide, or neuro-intermediate lobe ir-betaEP. 9alpha-fluorocortisol (0.2-200 mug/d) produced plasma, anterior pituitary, and hypothalamic effects equivalent to dexamethasone, but with one-tenth the potency. Unlike dexamethasone, higher doses of 9alpha-fluorocortisol significantly elevated neuro-intermediate lobe ir-betaEP. Deoxycorticosterone (2-2,000 mug/d) produced no significant changes in plasma, anterior pituitary or hypothalamic levels of either peptide; like 9alpha-fluorocortisol, doses of >60 mug/d significantly elevated neuro-intermediate lobe ir-betaEP. Whereas ir-ACTH and ir-betaEP synthesis in and release from the anterior pituitary are under complex negative feedback glucocorticoid control, there exists a mineralocorticoid-specific effect on neuro-intermediate lobe content of ir-betaEP.
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PMID:Glucocorticoid and mineralocorticoid effects on adrenocorticotropin and beta-endorphin in the adrenalectomized rat. 627 99

Bromocriptine treatment in rats (3 mg/kg per day, 7 days) significantly reduced alpha-msh and aldosterone plasma levels 2 hrs after the final treatment in animals on low, normal and high sodium diets. Alpha-MSH dose response curves for corticosterone and 18-hydroxydeoxycorticosterone (18-OH-DOC) in subsequently incubated glomerulosa cells gave stimulation at lower concentrations of alpha-MSH (10(-10) moles per litre) than in cells from untreated animals (10(-9) moles per 1). Curves for aldosterone (ald) and 18-hydroxycorticosterone (18-OH-B) were also affected in cells from animals on a low sodium diet. Fasciculata-reticularis cell responses to ACTH were unaffected. Metoclopramide (4 mg/kg per day, 7 days) elevated plasma alpha-MSH, although ald was unaffected, but inhibited the glomerulosa cell response to alpha-MSH in vitro. Acute dopaminergic responses in plasma ald may be mediated through alpha-MSH in rats, but chronically alpha-MSH may down- regulate glomerulosa cell alpha-MSH receptors. It is unlikely that alpha-MSH mediates the adrenocortical response to sodium depletion.
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PMID:Dopaminergic control of aldosterone: modulation of the response of rat adrenal zona glomerulosa cells to alpha-Msh by pretreatment with bromocriptine or metoclopramide. 628 Mar 45

alpha-MSH stimulates steroid secretion by rat adrenal zona glomerulosa cells and tissues but not fasciculata/reticularis cells when added to in vitro incubations. With glomerulosa cells from control animals on a normal sodium intake, production of corticosterone was significantly stimulated at an alpha-MSH concentration of 10(-9) moles per 1, with ED50 at 10(-8) moles per 1. Other steroid products, including 18-hydroxycorticosterone (18-OH-B), 18-hydroxydeoxycorticosterone (18-OH-DOC) and aldosterone were only significantly stimulated at 10(-7) moles alpha-MSH per 1. In contrast, in cells taken from animals subjected to dietary sodium restriction, aldosterone and 18-OH-B were significantly stimulated at 10(10) moles alpha-MSH per 1, whereas corticosterone and 18-OH-DOC were unaffected at all concentrations tested. Circulating plasma levels of alpha-MSH in control animals were 2.5 +/- 0.4 x 10(-10) moles per 1, but were unchanged by dietary sodium restriction or by sodium loss induced by diuretic (LASIX) administration. However, the threshold concentration at which alpha-MSH induces increased aldosterone secretion in cells from sodium depleted rats clearly falls well within the physiological range, and it is therefore likely that alpha-MSH contributes to the support of aldosterone secretion in these animals in vivo.
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PMID:alpha-MSH at physiological concentrations stimulates "late pathway" steroid products in adrenal zona glomerulosa cells from sodium restricted rats. 729 Oct 40

The effects and mechanisms of aging on corticosterone secretion in zona fasciculata-reticularis (ZFR) cells of ovariectomized (Ovx) rats were studied. Young (3-month) and old (24-month) female rats were Ovx for 4 days before decapitation. ZFR cells were isolated and incubated with different hormones or reagents at 37 degrees C for 30 min. Aging increased the basal secretion of corticosterone both in vivo and in vitro. The adrenocorticotropin (ACTH)-, forskolin-, 3-isobutyl-l-methylxanthine (IBMX)-, 8-bromo-adenosine 3',5'-cyclic monophosphate (8-Br-cAMP)-, and ovine prolactin (oPRL)-stimulated release of corticosterone by ZFR cells was greater in old than in young Ovx rats. H89, an inhibitor of protein kinase A (PKA), decreased the production of corticosterone in ZFR cells from young but not old Ovx rats. Forskolin-, or IBMX-induced production of cAMP was greater in old than in young Ovx animals, which correlated with the increase of corticosterone production by aging. The activity of 11 beta-hydroxylase that converts deoxycorticosterone (DOC, 10(-9) or 10(-8) M) to corticosterone in rat ZFR cells was decreased by age. However, the corticosterone production in response to high dose of DOC (10(-7) M) was indifferent between young and old groups. These results suggest that aging increases corticosterone production in Ovx rats via a mechanism in part associated with an increase of adenylyl cyclase activity and a decrease of phosphodiesterase activity, and then an increase of the generation of cAMP, but not related to either PKA activity or 11 beta-hydroxylase.
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PMID:Involvement of cAMP but not PKA in the increase of corticosterone secretion in rat zona fasciculata-reticularis cells by aging. 1189 48


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