Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate a possible pathophysiological role of human adrenomedullin (AM), we measured the plasma concentration of immunoreactive-AM (ir-AM) in 38 patients with end-stage renal disease (ESRD) on hemodialysis (HD) and 38 healthy subjects (age and sex matched). In addition, plasma ir-AM was characterized by a reverse-phase high performance liquid chromatography. The mean value (+/- SEM) of plasma AM in the patients before HD (10.1 +/- 0.67 fmol/ml) was markedly higher than that in the control group (2.9 +/- 0.13 fmol/ml, p < 0.001), but plasma AM levels were not altered by HD. There was a significant correlation between plasma AM levels and mean blood pressure (MBP) in a group of subjects including both patients before HD and healthy subjects (p < 0.01). In chromatographic study, the major peak of ir-AM in the plasma from patients on HD, as well as healthy subjects, emerged at an elution time identical to that of synthetic AM, indicating that the active form of AM was present in the circulating blood. The secretion of AM seemed to be increased in response to the conditions elicited by ESRD such as hypervolemia and/or hypertension, and reduced renal excretion of the peptide may also contribute to its high plasma level.
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PMID:Plasma concentration of human adrenomedullin in patients on hemodialysis. 871 51

Proadrenomedullin N-terminal 20 peptide (PAMP) and adrenomedullin (AM), which are both derived from proadrenomedullin, exhibit marked hypotensive effects. We recently reported that PAMP but not AM reduced the release of norepinephrine from peripheral sympathetic nerve endings. Our present objective was to clarify the involvement of the sympathetic nervous system in the hypotensive action of PAMP and AM. Intravenous administration of PAMP (10, 20, and 50 nmol/kg) to conscious rats induced less reflex tachycardia (5 +/- 5, 10 +/- 5, and 14 +/- 6 beats per minute [bpm]) than that of AM in 0.1, 0.5, and 1.0 nmol/kg doses (5 +/- 8, 20 +/- 7, and 38 +/- 5 bpm, P < .01) although both agents showed similar hypotensive effects. We evaluated the effect of PAMP on blood pressure in pithed rats whose sympathetic nervous systems were abolished. In pithed rats, AM (-2 +/- 1, -7 +/- 1, and -10 +/- 3 mm Hg; NS, P < .05, and P < .01, respectively) but not PAMP evoked hypotension. In contrast, administration of PAMP (-3 +/- 1, -11 +/- 2, and -14 +/- 4 mm Hg; P < .05, P < .01, and P < .01, respectively) as well as adrenomedullin (-2 +/- 2, -10 + 3, and -15 +/- 4 mm Hg; NS, P < .01, and P < .01) significantly reduced blood pressure in electrically stimulated, pithed rats, which had reached almost the same levels as in conscious rats. In electrically stimulated, pithed rats, plasma norepinephrine level was reduced by PAMP but not by vehicle or AM. These findings suggest that the hypotensive effect of PAMP is mainly due to inhibition of peripheral sympathetic nerve activity.
Hypertension 1996 Sep
PMID:Hypotensive effect of a newly identified peptide, proadrenomedullin N-terminal 20 peptide. 879 11

Although initially described in human pheochromocytoma, adrenomedullin has been isolated in several animal and human peripheral organs, including cardiovascular tissues. In experimental models, adrenomedullin exerts potent vasodilatory and natriuretic properties which could participate to maintain physiological cardiovascular and renal homeostasis. Whether adrenomedullin is powerful in humans remains to be proven. On the basis of increased plasma levels in hypertension and heart failure, adrenomedullin is suspected to contribute to the pathogenesis of these diseases. A reduced clearance is another possibility but has not yet been investigated in these pathological states. Finally, the ubiquitous distribution of adrenomedullin suggest various other biological activities that need to be established in future.
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PMID:Adrenomedullin: view on a novel vasodilatory peptide with natriuretic properties. 881 9

Hypoxia decreases vasorelaxation and leads to pulmonary arterial hypertension. A newly identified 52 amino-acid peptide adrenomedullin (ADM) exerts vasodilator effect in intact animals under normoxic condition. We studied the effect of human ADM on rat pulmonary arterial and aortic rings under normoxic and hypoxic conditions. During normoxia, ADM caused a concentration-dependent relaxation of precontracted aortic and pulmonary arterial rings; the relaxation was much more pronounced in pulmonary arterial rings and was abolished by the nitric oxide (NO) synthesis inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) and by deendothelialization. A fragment of ADM, ADM13-52, caused a degree of relaxation similar to that induced by ADM in pulmonary arterial rings, but not in the aortic rings, and the relaxation of pulmonary artery caused by ADM13-52 was not affected by the cyclooxygenase inhibitor indomethacin but was abolished by L-NAME and by deendothelialization. During hypoxia, ADM13-52 failed to relax pulmonary arterial rings, whereas ADM caused modest relaxation of pulmonary arterial rings (one third of the relaxation during normoxia), which was abolished by pretreatment with indomethacin. Our results indicate that the vasorelaxant effect of ADM is more pronounced in pulmonary artery than in the aorta; ADM has more potent vasodilator effect than ADM13-52 during hypoxia; ADM relaxes hypoxic pulmonary artery through an indomethacin-sensitive pathway; amino acids 1-12 in ADM must be present for relaxation of chronic hypoxic pulmonary arterial rings; and last, the presence of endothelium is necessary for the expression of ADM-mediated relaxation.
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PMID:Adrenomedullin dilates rat pulmonary artery rings during hypoxia: role of nitric oxide and vasodilator prostaglandins. 887 94

We have discovered a novel hypotensive peptide, designated "adrenomedullin", in human pheochromocytoma extracts. It has potent and long-lasting vasodilatory effects in several vascular systems. In addition to adrenomedullin, another hypotensive peptide, termed PAMP, is also produced from the adrenomedullin precursor. Although initially isolated from human pheochromocytoma and porcine adrenal medullary tissue, adrenomedullin mRNA is highly expressed in several peripheral organs including cardiovascular tissues. Taken together with the presence of adrenomedullin-specific receptors on VSMCs and the significant increase in plasma immunoreactive adrenomedullin levels in patients with hypertension, renal failure and congestive heart failure, adrenomedullin may participate in the pathogenesis of these diseases as a factor regulating blood pressure and circulation.
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PMID:Adrenomedullin: a new modulator of vascular tone. 895 71

Human adrenomedullin, a novel hypotensive peptide, contains a six-member ring structure similar to that found in calcitonin gene-related peptide and pancreatic amylin. Unlike the full-sequence peptide, human adrenomedullin-(15-22) [hADM-(15-22)], which contains the ring structure, increases systemic arterial pressure in the rat but not the cat. We undertook the present study to investigate the mechanism by which hADM-(15-22) increases systemic arterial pressure in the rat. Injection of hADM-(15-22) in doses of 10 to 300 nmol/kg i.v. increased systemic arterial pressure in a dose-dependent manner and was threefold less potent than norepinephrine when doses were compared on a nanomole basis. However, the ring structures of human calcitonin gene-related peptide and human amylin, human calcitonin gene-related peptide-(1-8) and human amylin-(1-8), respectively, had no significant effect on systemic arterial pressure in the rat. Pressor responses to hADM-(15-22) were reduced significantly after administration of phentolamine or reserpine. Responses to hADM-(15-22) were not altered by the angiotensin type 1 blocking agent DuP 753 or the endothelin-A/endothelin-B receptor blocking agent bosentan, and responses to hADM-(15-22) and the nicotinic agonist 1,1-dimethyl-4-phenylpiperazinium (DMPP) were reduced after bilateral adrenalectomy. Pressor responses to DMPP were reduced by hexamethonium, whereas the nicotinic blocking agent had no effect on the pressor response to hADM-(15-22). These data suggest that increases in systemic arterial pressure in response to hADM-(15-22) in the rat are mediated by the activation of alpha-adrenergic receptors by catecholamines released from the adrenal medulla. The present data suggest that hADM-(15-22) releases catecholamines from the adrenal medulla by a noncholinergic mechanism.
Hypertension 1996 Dec
PMID:Catecholamine release mediates pressor effects of adrenomedullin-(15-22) in the rat. 895 94

Adrenomedullin is a potent vasodilator peptide that exerts major effects on cardiovascular function. Adrenomedullin is biosynthesized in a wide variety of organs and cells, although it was initially isolated from human pheochromocytoma tissue. In addition to adrenomedullin, proadrenomedullin N-terminal 20 peptide was found to be processed from adrenomedullin precursor. Both adrenomedullin and proadrenomedullin N-terminal 20 peptide show hypotensive effects in anesthetized rats, but exhibit different hypotensive mechanisms. Further, adrenomedullin possesses multiple biological effects involved in cardiovascular homeostasis. Plasma adrenomedullin concentration is increased in patients with cardiovascular diseases such as hypertension, congestive heart failure, renal failure and septic shock. The present review summarizes the recent advancement of adrenomedullin research and demonstrates that adrenomedullin is one of the important vasoactive peptides involved in the physiology and pathophysiology of circulatory control and control of body fluid.
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PMID:Adrenomedullin--physiological regulator of the cardiovascular system or biochemical curiosity? 905 59

PROPERTIES OF ADRENOMEDULLIN: We have identified a novel hypotensive peptide, adrenomedullin, in human pheochromocytoma extract. It has potent and long-lasting vasodilatory effects in several vascular systems. In addition to adrenomedullin, another hypotensive peptide, proadrenomedullin-derived peptide (PAMP), was also found to be processed from the adrenomedullin precursor. PAMP inhibits neural transmission at peripheral sympathetic nerve endings, although adrenomedullin directly dilates vascular smooth muscle. POSSIBLE INVOLVEMENT IN PATHOGENESIS: Although initially isolated from human pheochromocytoma tissue, adrenomedullin messenger RNA is highly expressed in several peripheral organs, including cardiovascular tissues. Adrenomedullin and PAMP are both synthesized and secreted from vascular smooth muscle and endothelial cells, and they participate in circulation control through different mechanisms. Taken together with the presence of adrenomedullin-specific receptors on vascular smooth muscle cells and the significant increase in plasma immunoreactive adrenomedullin levels in patients with hypertension, renal failure and congestive heart failure, adrenomedullin may be involved in the pathogenesis of these diseases.
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PMID:Adrenomedullin: a new hypotensive peptide. 912 Jun 66

The purpose of this study was to investigate the effect of exercise on plasma concentrations of adrenomedullin, brain natriuretic peptide (BNP), and atrial natriuretic peptide (ANP) in patients with essential hypertension (n = 15) and in normotensive controls (n = 10). Exercise consisted of two fixed workloads, 40 and 80 watts of work load using a supine bicycle ergometer. Plasma levels of all three peptides at rest were significantly higher in hypertensives than in controls. Plasma concentrations of ANP increased with exercise in both groups and had greater increments in hypertensive patients than in normotensives. Plasma concentrations of BNP increased only in patients with hypertension and the levels of increase correlated with basal plasma BNP levels (r = 0.94, p < 0.001) and with left ventricular mass (r = 0.62, p < 0.01) determined by echocardiography. In contrast, plasma adrenomedullin did not change with exercise in either group. These results suggest that secretion patterns of these peptides are regulated by different mechanisms and that the amount and kind of peptides mobilized by exercise may depend on the underlying diseases or pathophysiologic condition.
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PMID:Different secretion patterns of adrenomedullin, brain natriuretic peptide, and atrial natriuretic peptide during exercise in hypertensive and normotensive subjects. 914 Jul 11

The recently discovered peptide adrenomedullin (AM) alters blood pressure through effects on the resistance vessels. Moreover, AM modifies the secretion of corticotropin and aldosterone and could thereby indirectly influence blood pressure through the renin-angiotensin-aldosterone system. Although plasma AM and renin concentration have been found to directly correlate, a causal linkage between AM and renin has not been shown. The present study tested the influence of AM on renin secretion and renin gene expression by renal juxtaglomerular granular cells. Prominent expression and release of AM by vascular structures has been reported; therefore, we investigated the local expression of AM in juxtaglomerular structures. Renin release from isolated perfused rat kidneys was dose-dependently increased by AM (1 to 30 nmol/L), whereas renal perfusate flow rate increased up to 17% at a constant perfusion pressure of 100 mm Hg. In primary cultures of mouse granular cells, AM augmented renin release, renin mRNA accumulation, and cAMP production in a dose- and time-dependent manner (threshold values in the range 10 pmol/L to 1 nmol/L). By reverse transcription-polymerase chain reaction, significant expression of the AM gene was detected in microdissected rat glomeruli with afferent arterioles and in primary cultures of mesangial and granular cells. We conclude that AM is expressed in juxtaglomerular structures and that it has a direct stimulatory effect on renin secretion and renin mRNA abundance by receptors on juxtaglomerular cells, possibly through increases in cAMP. AM could act as an autocrine/paracrine stimulatory factor in the control of renin secretion and renin gene expression.
Hypertension 1997 May
PMID:Adrenomedullin stimulates renin release and renin mRNA in mouse juxtaglomerular granular cells. 914 80


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