Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0031511 (pheochromocytoma)
 14,622 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adrenomedullin (ADM) release is enhanced in pheochromocytoma, chronic heart failure (HF), hypertension and renal diseases. This study was designed to test the hypothesis that ADM secretion increases also in response to acute stimuli, such as static effort and to compare plasma ADM response to this stimulus in patients with chronic HF and healthy persons. Eight male HF patients (II/III class NYHA) and eight healthy subjects (C) performed two 3-min bouts of static handgrip at 30% of maximal voluntary contraction, alternately with each hand without any break between the bouts. At the end of both exercise bouts and in 5 min of the recovery period, plasma ADM and catecholamines were determined. In addition, heart rate, blood pressure, and stroke volume (SV) were measured. The baseline plasma ADM and noradrenaline levels were higher, whilst plasma adrenaline and SV were lower in HF patients than in C group. The 1st exercise bout caused an increase in plasma ADM from 3.32 +/- 0.57 to 4.98 +/- 0.59 pmol l(-1) (p<0.01) in C and from 6.88 +/- 0.58 to 7.80 +/- 0.43 pmol x l(-1) (p<0.02) in HF patients. The 2nd exercise bout did not produce further elevation in plasma ADM and during recovery the hormone concentration declined to pre-exercise or lower values. There were no differences between groups in exercise-induced increases in plasma ADM. Plasma ADM correlated with SV (r = -0.419) and with noradrenaline concentrations (r = 0.427). It is concluded that static exercise causes the short-lasting increase in plasma ADM concentration which is similar in healthy subjects and in patients with mild heart failure.
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PMID:Effect of static handgrip on plasma adrenomedullin concentration in patients with heart failure and in healthy subjects. 1212 Aug 96

Antigen challenge can provoke acute bronchoconstriction, recognized as immediate asthmatic response (IAR), but the evolving events in this reaction are not well defined. Recently, a novel peptide, designated adrenomedullin, was isolated from human pheochromocytoma, and has been shown to have potent systemic and pulmonary vasodilator activity.The purpose of this study was to elucidate the influence of adrenomedullin in the development of IAR. Passively sensitized guinea pigs were anesthetized and treated with diphenhydramine hydrochloride, and then artificially ventilated. Ovalbumin was inhaled after an intravenous administration of adrenomedullin. Other studies were performed in naive guinea pigs to investigate the airway responses to inhaled methacholine or histamine after an intravenous administration of adrenomedullin. Antigen challenge caused bronchoconstriction in sensitized guinea pigs. Adrenomedullin did not inhibit the antigen-induced bronchoconstriction in sensitized guinea pigs or the dose-dependent responses to inhaled methacholine or histamine in naive animals in spite of its vasodilating effect. We conclude that an intravenous administration of adrenomedullin does not influence antigen-induced bronchoconstriction or bronchial responsiveness to inhaled methacholine or histamine in vivo.
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PMID:Lack of adrenomedullin on antigen-induced bronchoconstriction in guinea pigs in vivo. 1259 95

Adrenomedullin, originally discovered in human pheochromocytoma, has been shown to have potent vasodilatory activity. However, like other vasoactive peptide hormones, its physiological roles have been found to extend far beyond the regulation of vascular tonus, and to include such functions as the regulation of cell proliferation and differentiation. There is a growing body of evidence that adrenomedullin exerts a wide range of effects on cell growth and apoptotic death, and that these effects are dependent on cell type and experimental conditions. Signaling pathways independent of cyclic AMP, such as protein tyrosine kinase(s) and mitogen-activated protein kinases, may play key roles in the regulation of mitogenesis and apoptosis by adrenomedullin.
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PMID:Regulation of cell growth and apoptosis by adrenomedullin. 1263 Aug 6

Adrenomedullin (AM) and peptides of the proadrenomedullin N-terminal 20 peptide (PAMP20) family are multifunctional peptides abundantly expressed in the adrenal medulla. These peptides are released by regulated exocytosis along with catecholamines upon stimulation of adrenal chromaffin cells. They are also released gradually during culture, and this release is stimulated by a 3',5'-cyclic adenosine monophosphate (cAMP)-dependent pathway. The expression and release of AM increase under hypoxia in chromaffin cells. The expression of AM in pheochromocytoma PC12 cells is reduced during neuronal differentiation with nerve growth factor. On the other hand, PAMP20 and PAMP12 suppress catecholamine release and synthesis by interfering with nicotinic cholinergic receptors. AM increases blood flow in the adrenal gland, and causes a gradual release of catecholamine, but does not modify regulated exocytosis upon the stimulation of cells. Current data indicate that the expression of these peptides is regulated by intracellular signaling pathways, and changes under various physiological and pathological conditions. AM and PAMP20 family peptides have distinct physiological functions. PAMP20 and PAMP12 are endogenous peptides that modulate chromaffin cell function in an autocrine manner, whereas AM may mainly regulate vascular cell function in a paracrine manner.
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PMID:Pathophysiological function of adrenomedullin and proadrenomedullin N-terminal peptides in adrenal chromaffin cells. 1263 Aug 14

Adrenomedullin (AM), a potent vasodilator peptide originally isolated from pheochromocytoma, is expressed in cardiovascular tissues such as those of the cardiac atria and ventricles. Cell culture experiments have shown that AM peptide is synthesized and secreted from cardiac myocytes and fibroblasts of neonatal rats. Humoral factors, such as angiotensin II (Ang II) and endothelin-1 (ET-1), and mechanical stress due to pressure and volume overload to the heart have been shown to be involved in AM expression of the myocardium in both in vitro and in vivo studies. The effects of AM on cardiomyocytes and cardiac fibroblasts have been examined in in vitro studies, with the result that AM was shown to exert inhibitory actions on myocyte hypertrophy and on proliferation and collagen production of cardiac fibroblasts in an autocrine or paracrine manner. In rats, experimental therapeutic intervention consisting of transfer of the AM gene or of recombinant AM appears to partly inhibit the progression of cardiac hypertrophy and remodeling. It has been shown that the calcitonin receptor-like receptor (CRLR) and receptor-activity-modifying protein (RAMP) act together to function as AM receptors, although in this regard there are a number of issues, including the cellular mechanism of AM actions, that remain to be addressed. In addition, the role of proadrenomedullin N-terminal 20 peptide (PAMP), which is derived from preproAM, is another topic for future experiments. Collectively, the research data accumulating in this area suggest that AM plays a role as an autocrine or paracrine hormone in the cardiac ventricles, and that AM might be utilized as a therapeutic tool in the treatment of hypertensive or ischemic heart disease.
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PMID:Adrenomedullin: a possible autocrine or paracrine hormone in the cardiac ventricles. 1263 Aug 21

Detrusor instability (DI) and detrusor-external sphincter dyssynergia lead to poor bladder emptying and high bladder pressure. Recent results indicate that nitric oxide (NO) is an important transmitter or messenger molecule in autonomic neurotransmission. Adrenomedullin (AM) is a potent vasodilator and natriuretic peptide, originally purified from human pheochromocytoma. Since NO and AM have vasodilatory effects on smooth muscles, we considered them to be of interest in children with DI. We determined the tissue levels of NO and AM in 14 children with DI, and compared these with 6 children with normal bladder activity. Bladder biopsy total nitrite levels (nmol/g tissue) were decreased in children with DI (10.69+/-0.91 vs. 12.83+/-0.98, P<0.01). However, AM levels (pmol/g tissue) were increased in the same patients (48.84+/-3.52 vs. 28.79+/-1.53, P<0.001). According to our results, decreased NO production probably has a role in the pathophysiology of DI, although increased AM appears to be compensatory. NO may provide a therapeutic target in clinical situations related to DI. However, the functional significance of AM and NO in bladder smooth muscle remains to be determined by further detailed studies.
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PMID:Adrenomedullin and nitric oxide in children with detrusor instability. 1268 57

Adrenomedullin is a potent vasodilator peptide originally isolated from a pheochromocytoma. Recently, a novel adrenomedullin receptor has been identified as a complex of calcitonin receptor-like receptor (CRLR) and receptor activity modifying protein 2 (RAMP2). To explore the pathophysiological roles of adrenomedullin and its receptor component RAMP2 in ischemic cardiovascular diseases, we studied the changes of adrenomedullin and RAMP2 mRNA in myocardium and aorta in rats with isoproterenol (ISO)-induced myocardial impairment. In ISO-treated rats, heart became enlarged markedly, the ratio of heart to body weight was increased by 54% (P<0.01), and myocardial malondialdehyde content and plasma lactate dehydrogenase activity was elevated by 43% (P<0.01) and 138% (P<0.01), respectively. Immunoreactive adrenomedullin (ADM) in plasma, myocardium and aorta was augmented by 116.7% (P<0.01), 50.8% (P<0.01) and 12.5% (P>0.05), respectively. ADM mRNA in myocardium and aorta was increased by 96.8% (P<0.01) and 38.5% (P<0.01), respectively. RAMP2 mRNA in myocardium and aorta was increased by 19.6% (P<0.05) and 15.8% (P<0.01), respectively. These results suggest that the increase of ADM level and the up-regulation of ADM and RAMP2 gene in myocardium and aorta may be significant in the pathogenesis of ischemic myocardiopathy.
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PMID:Changes of adrenomedullin and receptor activity modifying protein 2 (RAMP2) in myocardium and aorta in rats with isoproterenol-induced myocardial ischemia. 1273 46

Adrenomedullin (AM) is a multifunctional peptide in human pheochromocytoma. To evaluate whether AM could be an angiogenic factor, we examined its effect on kinases and angiogenic processes. AM induced tyrosine phosphorylation of Akt and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase1/2 (ERK1/2) by using distinct signaling pathways in human umbilical vein endothelial cells (HUVECs). AM also phosphorylated focal adhesion kinase, and phosphatidylinositol 3'-kinase inhibitor inhibited AM-induced focal adhesion kinase phosphorylation. Pretreatment with high concentrations of AM22-52, a putative AM receptor antagonist, partially suppressed AM-induced phosphorylation of Akt, ERK1/2, and focal adhesion kinase. AM and vascular endothelial growth factor produced increases in DNA synthesis and migration in HUVECs. AM induced tube formation in HUVECs, and its effect was inhibited by pretreatment with phosphatidylinositol 3'-kinase inhibitor or ERK1/2 inhibitor. AM induced sprouting in porcine pulmonary arterial endothelial cells and promoted neovessel formation in a mouse Matrigel plug assay. Inhibitors of phosphatidylinositol 3'-kinase and ERK1/2 inhibited AM-induced endothelial sprouting in vitro and angiogenesis in vivo. AM exerts angiogenic activity through activation of Akt, MAPK, and focal adhesion kinase in endothelial cells.
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PMID:Angiogenic role of adrenomedullin through activation of Akt, mitogen-activated protein kinase, and focal adhesion kinase in endothelial cells. 1289 63

Adrenomedullin (ADM) is a 52-amino acid peptide with structural homology to calcitonin gene-related peptide (CGRP) initially isolated from human pheochromocytoma. ADM is synthesized by many mammalian tissues including the adrenal medulla, endothelial and vascular smooth muscle cells, myocardium and central nervous system. ADM binds to plasma membrane receptors composed of calcitonin receptor-like receptor (CRLR), a member of serpentine receptor superfamily, and receptor activity modifying protein (RAMP) type 2 or 3. ADM has also some affinity for CGR(1) receptor composed of CRLR and RAMP1. ADM dilates blood vessels in both endothelium-dependent and independent manner and decreases systemic arterial pressure. Intrarenally administered ADM increases natriuresis by vascular and tubular mechanisms. In addition, ADM inhibits migration and proliferation of vascular smooth muscle cells and attenuates myocardial remodelling by inhibiting protein synthesis in cardiomyocytes and proliferation of cardiac fibroblasts. ADM is expressed in various tissues from early stage of embryogenesis and is also synthesized in placenta, uterus and fetal membranes. Plasma ADM level is increased in arterial hypertension, acute coronary syndromes, heart failure, renal diseases and septic shock, being involved in the pathophysiology of these disorders. Experimental ADM treatment is beneficial in arterial and pulmonary hypertension, heart failure, septic shock and ischemia/reperfusion injury. Proadrenomedullin N-terminal peptide (PAMP) is another product of ADM gene which is co-secreted by ADM-producing tissues, with some effects similar and some opposite to ADM.
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PMID:Adrenomedullin--what do we know 10 years since its discovery? 1504 74

Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are multi-functional peptides derived from the same precursor, proadrenomedullin. We have studied the regulatory mechanism of expression of these peptides during neuronal differentiation of rat pheochromocytoma PC12 cells by nerve growth factor (NGF). The cellular levels of the peptides increased slightly, and then progressively decreased below the control by NGF. Immunoreactive (ir)-AM in the medium was transiently increased by NGF. Cytochemical staining showed that ir-AM and ir-PAMP were abundantly present in cytoplasm in the undifferentiated cells, and were decreased during culture with NGF. There was no preferential localization of ir-AM or ir-PAMP in neurites in comparison with in cytoplasm in the differentiated cells. Northern blot analysis showed that mRNA encoding these peptides, as detected as a band of 1.6 kb, increased more than three-fold at 1 h after the addition of NGF and then progressively decreased to one fifth of the control during 72 h. Degradation rate of the mRNA was slowed by NGF even when mRNA level is decreased after 72 h of NGF treatment. The transcription rate of their gene increased transiently and then decreased by the long-term treatment with NGF. These results demonstrate that expression of AM and PAMP is regulated by NGF along with time-dependent differentiation: AM gene transcription is transiently activated by NGF, whereas it was suppressed during neuronal differentiation of the cells.
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PMID:Expression of adrenomedullin and proadrenomedullin N-terminal 20 peptide in PC12 cells after exposure to nerve growth factor. 1512 Aug 57


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