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)

Adrenomedullin was originally discovered in human pheochromocytoma but is now known to be widely distributed in various organs. Adrenomedullin is a potent vasodilatator peptide that exerts major effects on cardiovascular function. Plasma adrenomedullin concentration is increased in patients with cardiovascular disease such as hypertension, congestive heart failure, myocardial infarction, renal failure and other diseases. The present review summarizes the recent advances on adrenomedullin research and demonstrates that adrenomedullin is one of the important vasoactive peptides involved in the physiology and pathophysiology of cardiovascular system.
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PMID:[Adrenomedullin. A new peptide involved in the regulation of the cardiovascular system]. 1042 23

The novel hypotensive peptide, proadrenomedullin N-terminal 20 peptide (PAMP), is processed from the adrenomedullin precursor. Recently, we identified PAMP-12 [PAMP(9-20)] from the porcine adrenal medulla as a major endogenous and biologically active peptide. Using a new, sensitive radioimmunoassay which recognizes the C-terminal region of PAMP-20 [PAMP(1-20)], we investigated the role of PAMP in patients with essential hypertension who had normal renal function, and whether PAMP-12 is present in humans. The mean PAMP plasma concentration, like that of adrenomedullin, was significantly higher in hypertensive [1.51 fmol/mL, standard error of the mean (SEM) 0.09 fmol/mL] than normotensive participants (1.08 fmol/mL, SEM 0.05). The increase in plasma PAMP concentration in patients with organ damage accompanied by hypertension was significantly higher than that in patients without organ damage. The PAMP concentration had a significant positive correlation with mean blood pressure and adrenomedullin concentration. The immunoreactive PAMP in human tissue and plasma was characterized by reverse-phase high-performance liquid chromatography. PAMP-12, as well as PAMP-20, was abundant in the phaeochromocytoma tissue. These findings suggest that PAMP plays some pathophysiological role against the development of essential hypertension.
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PMID:Increased plasma proadrenomedullin N-terminal 20 peptide in patients with essential hypertension. 1050 13

The adrenomedullin (AM) peptide and the expression of AM messenger RNA (mRNA) from feto-maternal tissues of 22 normotensive pregnant women and from 7 women with pregnancy-induced hypertension (PIH) during third-trimester were examined to clarify the pathophysiological features of PIH. Samples of the placenta, uterine muscle, umbilical artery, and fetal membranes were obtained from each patients under informed consent. The AM peptide was measured by a radioimmunoassay and the AM mRNA level was analyzed by Northern hybridization. The total immunoreactive AM (fmol/mg wet tissue) was significantly increased in the fetal membranes (1.95+/-0.20 vs. 3.03+/-0.44) and the umbilical artery (0.11+/-0.01 vs. 0.15+/-0.02) of the patients with PIH. On the other hand, the AM mRNA level was higher in the umbilical artery, and lower in the fetal membranes in the patients with PIH. The present results thus suggest that the changes in the expression of AM in fetal membrane and umbilical artery in PIH may play an important role in the fetal and maternal circulation.
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PMID:Expression of adrenomedullin in feto-placental circulation of human normotensive pregnant women and pregnancy-induced hypertensive women. 1053 77

The aim of this study was to evaluate the effect of orthostasis on the time course of plasma adrenomedullin concentration. On 5 different days, normotensive subjects were randomized to undergo for 30 minutes either 12 degrees, 30 degrees, 53 degrees, or 70 degrees passive head-up tilt or to remain supine. Venous blood was collected from each subject in the supine position before tilting, at 3 and 27 minutes during tilting, and at 2 and 50 minutes after orthostasis. Plasma adrenomedullin increased significantly with tilt of >/=30 degrees in a stimulus-dependent manner. Approximately half of the increase seen at 27 minutes occurred during the first 2 minutes of upright positioning; the maximum effect with 70 degrees tilt was +70%. Elevations in norepinephrine, epinephrine, aldosterone, plasma renin activity, vasopressin, heart rate, and mean arterial pressure were also significant. Hematocrit, blood density, plasma density, and plasma volume loss rose (P<0.05) at 53 degrees and 70 degrees tilt. Our results indicate that adrenomedullin may play an important role in stabilization of hemodynamics during passive orthostasis. In conclusion, plasma adrenomedullin rapidly increases with orthostatic challenge in a stimulus-dependent manner and also swiftly returns to baseline levels after the subject resumes the supine position.
Hypertension 1999 Nov
PMID:Orthostatic stimuli rapidly change plasma adrenomedullin in humans. 1056 97

Adrenomedullin, which was discovered as a vasodilating peptide, has been reported to be produced in various organs, in which adrenomedullin regulates not only vascular tone but also cell proliferation and differentiation in an autocrine/paracrine manner. We evaluated the effect of adrenomedullin on endothelial cell apoptosis. Human umbilical vein endothelial cells underwent apoptosis when cultured in serum-free medium. Treatment with adrenomedullin reduced the number of cells with pyknotic nuclei (Hoechst 33258 staining) and inhibited cell death (dimethylthiazol-diphenyltetrazolium bromide assay) in a dose-dependent manner. The administration of adrenomedullin did not alter the expression levels of Bcl-2 family proteins. Experiments with analogs of cAMP or a cAMP-elevating agonist demonstrated that elevation of the intracellular cAMP concentration does not mediate the antiapoptotic effect of adrenomedullin. The coadministration of N-nitro-L-arginine methyl ester (2 mmol/L), an inhibitor of nitric oxide synthase, abrogated the effect of adrenomedullin. Lower doses of sodium nitroprusside (1 to 10 micromol/L), a nitric oxide donor, mimicked the antiapoptotic effect of adrenomedullin. The antiapoptotic effect of sodium nitroprusside was not attenuated by the inhibition of soluble guanylyl cyclase with 1 micromol/L oxadiazolo-quinoxalin-1-one nor could apoptosis be inhibited by the incubation of human umbilical vein endothelial cells with 1 mmol/L 8-bromo-cGMP, a cell-permeant cGMP analog. These results indicate that adrenomedullin and nitric oxide inhibit endothelial cell apoptosis via a cGMP-independent mechanism.
Hypertension 2000 Jul
PMID:Adrenomedullin and nitric oxide inhibit human endothelial cell apoptosis via a cyclic GMP-independent mechanism. 1090 17

We investigated the potential role of increased plasma adrenomedullin and brain natriuretic peptide (BNP) levels in a patient with malignant hypertension. A 51-year-old man was admitted to our hospital with a chief complaint of visual disturbance. His blood pressure was 270/160 mmHg on admission. Papillary edema associated with retinal bleeding was observed. Echocardiography revealed marked concentric left ventricular hypertrophy with mild systolic dysfunction. Plasma levels of adrenomedullin and BNP were markedly elevated. Antihypertensive therapy reduced the plasma levels of adrenomedullin in association with a concomitant decrease in blood pressure. The plasma level of BNP also decreased and regression of left ventricular hypertrophy and normalization of left ventricular systolic function were observed. Our findings suggest that adrenomedullin may be involved in the defense mechanism against further elevations in blood pressure in patients with hypertension and that the plasma level of BNP may reflect left ventricular systolic dysfunction, left ventricular hypertrophy, or both, in patients with severe hypertension.
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PMID:Antihypertensive therapy reduces increased plasma levels of adrenomedullin and brain natriuretic peptide concomitant with regression of left ventricular hypertrophy in a patient with malignant hypertension. 1096 2

Levels of adrenomedullin (AM) have been shown to be elevated in hypertension and chronic renal failure, suggesting that AM plays a role in the pathogenesis of these diseases. The objective of the present study was to investigate whether circulating AM is involved in erythropoietin (Epo)-induced hypertension in patients with renal anemia due to progressive renal disease. Following treatment with 6,000 IU of Epo once a week, the hematocrit (Ht) rose significantly from 25.9+/-4.0 to 33.4+/-3.3% (n=54, p<0.001) with an overall rate of increase in Ht of 0.43+/-0.04%/week. In response to treatment with Epo, a rise in mean blood pressure of >10 mmHg (Epo-induced hypertension) was found in 22% (12/54 cases) of the patients enrolled. There was no difference in the rate of Ht increase between patients with and without Epo-induced hypertension. There was a significant positive correlation between mature AM and serum creatinine (Cr) concentration before treatment with Epo. However, no correlation was found between the plasma concentration of total AM and serum Cr concentration. Long-term treatment with Epo did not influence plasma concentration of either mature AM or total AM in patients developing hypertension during the study period. These results suggest that circulating AM may play a role in the progression of renal disease. However, the present study does not support the notion that circulating AM is associated with the pathogenesis of Epo-induced hypertension. It is too early yet to claim that there is no AM-mediated mechanism in Epo-induced hypertension.
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PMID:Circulating adrenomedullin in erythrocopietin-induced hypertension. 1101 96

We examined the effects of the vasodilator peptide adrenomedullin (AM) infused intravenously into subjects with essential hypertension. Eight men 39 to 58 years old with uncomplicated hypertension (147/96+/-5/3 mm Hg at baseline) were studied in a placebo-controlled, crossover design. Each subject received intravenous AM in a low and a high dose (2.9 and 5.8 pmol. kg(-1). min(-1) for 2 hours each) or vehicle-control (Hemaccel) infusion in a random order on day 4 of a controlled metabolic diet (80 mmol/d Na(+), 100 mmol/d K(+)). Plasma AM reached pathophysiological levels during infusion (18+/-4 pmol/L in low dose, 34+/-9 pmol/L in high dose) with a concurrent rise in plasma cAMP (+8.4+/-1.2 pmol/L, P:<0. 05 compared with control). Compared with control, high-dose AM increased peak heart rate (+17.8+/-2.3 bpm, P<0.01), lowered systolic (-24.6+/-0.9 mm Hg; P<0.01) and diastolic (-21.9+/-1.4 mm Hg; P<0.01) blood pressure, and increased cardiac output (+1.0+/-0. 1 L/min in low dose, +2.9+/-0.2 L/min in high dose; P<0.01 for both). Despite a rise in plasma renin activity during high dose (P<0.05), aldosterone levels did not alter. Plasma norepinephrine levels increased 1295+/-222 pmol/L (P<0.001) and epinephrine increased 74+/-15 pmol/L (P<0.05) with high-dose AM compared with control. AM had no significant effect on urine volume and sodium excretion. In subjects with essential hypertension, the intravenous infusion of AM to achieve pathophysiological levels produced significant falls in arterial pressure, increased heart rate and cardiac output, and stimulated the sympathetic system and renin release without concurrent increase in aldosterone. Urinary parameters were unaltered. Although AM has potent hemodynamic and neurohumoral effects in subjects with essential hypertension, the threshold for urinary actions is set higher.
Hypertension 2000 Oct
PMID:Hemodynamic, hormone, and urinary effects of adrenomedullin infusion in essential hypertension. 1104 Feb 40

Monolayer of endothelial cells that cover the vascular channels are the major regulator of haemo-vascular homeostasis. Endothelium secretes the chemical factors that affect contraction of the muscular vascular cells, permeability of tissue, blood fluidity, intercellular interaction in vascular structure of the channel as a whole and of different regions. In its turn, the secretory function of endothelial cells is stimulated by mechanical or hormonal factors under a feedback system principle. Special features of morphology and biochemistry of vascular endothelium cells determine the micro-organs heterogeneity of the vascular channel depending on phenotine, gene expression, size and growth of endothelium cells. On this basis the processing biochemical disintegration develop either selectively or in a generalised form, and results in development of endothelial dysfunctions, as the original factor of many cardiovascular pathologies. Endothelial disfunction is a systemic pathology related to pathology of microstructure and hormonal function of endothelial cells representing a major tissue system of the vascular channel. Formation of hypertension states, ischemic cardiopathology, haemostasis changes, metabolic pathology (hypercholesterinemia and hyperglycemia) that lead to pathogenesis of arteriosclerosis, diabetes (etc.) as result of modified function of endothelium, and above all, pathology of production by dilator and constrictor substances, and the factors regulating interaction of endothelium with blood cells. The basic mechanism for development of the endothelial dysfunction is related to modification of synthesis and releasing of nitrogen oxide, a key regulator of the endothelial-vasal system. Physiologically active peptides (angiotensin II, endothelin-I, bradykinin, adrenomedullin and ANP) contribute to development of the processes related to the endothelium function and dysfunction. An important role is played, apparently, by growth peptide factors and specific proteins of cellular adhesion and membrane interaction--to integrins and selectins.
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PMID:[The molecular and physiological aspects of endothelial dysfunction. The role of endogenous chemical regulators]. 1109 97

Hypertension is a frequent finding in uremic patients. The pathogenesis of this complication in uremia is complex and not fully elucidated. An imbalance between the vasoconstrictor and vasodilator systems may be involved in its pathogenesis. In this study we have evaluated the state of nitric oxide (NO) and adrenomedullin (ADM) in hemodialyzed patients, especially those with hypertension. We included a group of hypertensive hemodialyzed patients (n = 9) and a group of normotensive control patients (n = 10). We measured plasma renin activity, as well as plasma catecholamines, ADM, and nitrite/nitrate levels in basal conditions before starting the hemodialysis session. Plasma volume, as well as left ventricular ejection fraction were also measured. Hemodialysis patients showed plasma levels of nitrite/nitrates and ADM higher than the reference values in the normal population. We observed no differences in the plasma levels of nitrite/nitrates, but ADM levels were higher in hypertensive (278.2 +/- 15.5 pg/ml) patients than in normotensive patients (225 +/- 9.9 pg/ml) (p < 0.05). When considering all patients together, mean arterial pressure positively correlated with plasma ADM (r = 0.468, p < 0.05). Plasma volume and left ventricular ejection fraction were similar in the two groups of patients. In summary, plasma levels of nitrite/nitrates and ADM are increased in hemodialyzed patients, although only ADM levels were further increased in hypertensive patients. Our results do not suggest that a decreased production in the vasodilator factors evaluated is involved in the pathogenesis of hypertension in uremic patients.
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PMID:[Increased adrenomedullin levels in hypertensive patients on maintenance hemodialysis]. 1110 Jun 63


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