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) is a new 52 amino acid peptide originally isolated from extracts of human pheochromocytoma. ADM's biologic properties are nearly identical to those of atrial natriuretic peptides. Thus, the 4 peptide hormones originating from amino acids 1-30 [long acting natriuretic peptide], 31-67 [vessel dilator], 79-98 [kaliuretic peptide] and 99-126 [atrial natriuretic factor; ANF] of the 126 amino acid ANF prohormone as well as ADM have blood pressure lowering and diuretic properties. The present investigation was designed to determine if one or more of these 4 atrial natriuretic peptides increase adrenomedullin within the circulation of healthy humans. Infusion of 100 ng/kg body weight/minute for 60 minutes of the respective atrial peptides resulted in a 4-fold (P < 0.001) increase in the circulating concentration of adrenomedullin secondary to the ANF infusion but no increase in adrenomedullin with the long acting natriuretic peptide, vessel dilator, or kaliuretic peptide infusions. The four-fold increase of adrenomedullin in the circulation persisted throughout the infusion of ANF, but returned to pre-infusion levels within 30 minutes of stopping the ANF infusion. Infusion of 10 pg/kg body weight/minute for 60 minutes of ANF resulted in a 2 1/2-fold increase (P < 0.05) in the circulating concentration of adrenomedullin. There was a significant (P < 0.01) diuresis and blood pressure lowering effect with each of the atrial natriuretic peptides in the present investigation. This investigation suggests that 1) atrial natriuretic factor increases the release of adrenomedullin and 2) that the diuretic and blood pressure lowering effects previously attributed to atrial natriuretic factor may be partially due to adrenomedullin since both increased during the ANF infusion and both have similar biologic effects. As opposed to atrial natriuretic factor, adrenomedullin was not increased by long acting natriuretic peptide, vessel dilator, or kaliuretic peptide suggesting that their biologic effects do not involve adrenomedullin.
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PMID:Atrial natriuretic peptide increases adrenomedullin in the circulation of healthy humans. 869 35

Adrenomedullin is a fifty-two-amino acid polypeptide that was first discovered in pheochromocytoma cells, and later in the normal adrenal medullae, lungs, kidneys, and blood. In mammals, adrenomedullin has vasodepressive effects, mainly by decreasing peripheral vascular resistance. I investigated the effects of adrenomedullin in fish to see if this novel neuropeptide would have an effect in lower vertebrates, or if its actions were limited to the higher vertebrates. Bolus injections of adrenomedullin resulted in a reduction of heart rate and dorsal aortic pressure in the rainbow trout Oncorhynchus mykiss. However, adrenomedullin had no effect in the Atlantic cod, Gadus morhua. The effects of adrenomedullin in trout appear to be due to a direct action on the peripheral vasculature, as pre-treatment of celiac artery strips with tetrodoxin had no effect on the ability of adrenomedullin to relax the strip.
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PMID:Cardiovascular effects of adrenomedullin in teleost fishes. 872 51

Adrenomedullin is a potent vasodilator peptide that was isolated from pheochromocytoma. Localization of adrenomedullin-like immunoreactivity was studied by immunocytochemistry in the human hypothalamus and adrenal gland. Adrenomedullin-immunoreactive cell bodies were found in the paraventricular, supraoptic and infundibular nuclei of the hypothalamus. Both magnocellular and parvocellular cells of the paraventricular nucleus were positively immunostained. Adrenomedullin-like immunoreactivity was localized in the adrenal medulla. No positive immunostaining was observed in the vascular endothelium, vascular smooth muscle cell or adrenal cortex. The preabsorption of the antiserum with synthetic human adrenomedullin (1-52) abolished the immunostaining. These findings indicate that adrenomedullin-like immunoreactivity is localized in the paraventricular, supraoptic and infundibular nuclei as well as in the adrenal medulla, and suggest that adrenomedullin acts as a neurotransmitter, a neuromodulator or a neurohormone in the human hypothalamus.
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PMID:Immunocytochemical localization of adrenomedullin-like immunoreactivity in the human hypothalamus and the adrenal gland. 874 29

Adrenomedullin (AM), a potent and novel vasodilator 52-residue peptide originally isolated from pheochromocytoma, is processed from a precursor molecule (preproAM) in which another unique 20-residue sequence, termed proadrenomedullin N-terminal 20 peptide (PAMP), exists. Using [125I Tyr0] rat PAMP as a radioligand, we have examined PAMP binding sites in various rat tissues and cultured vascular smooth muscle cells (VSMC) from rat aorta. Specific binding sites for rat PAMP, although very low, were widely distributed in various rat tissues examined. The relatively more abundant sites were present in aorta and adrenal glands, followed by lung, kidney, brain, spleen, and heart. An equilibrium binding study using cultured rat VSMC revealed the presence of a single class of high-affinity [dissociation constant (Kd): 3.5 x 10(-8) M] binding sites for rat PAMP with a maximal binding capacity of 4.5 x 10(6) sites per cell. Binding studies revealed that synthetic rat PAMP(1-19)-NH2 was about 10-fold less potent, and rat PAMP(1-20)-OH and human PAMP were about 20-fold less potent than rat PAMP(1-20)-NH2. SDS-polyacylamide gel electrophoresis after affinity-labeling of membranes from various rat tissues (aorta, adrenal glands, lung) and VSMC revealed a distinct labeled band with the apparent molecular mass of 90 kDa, which was diminished by excess unlabeled rat PAMP. A nonhydrolyzable GTP analog (GTP-gammaS) dose-dependently reduced binding of [125I] rat PAMP to VSMC membranes, while ATP-gammaS had no effect. Neither cyclic AMP nor inositol-1,4,5-triphosphate formation was affected by rat PAMP in rat VSMC. The present study demonstrates for the first time that PAMP receptors are widely distributed in various rat tissues, among which aorta and adrenal glands have the most abundant sites. Our data suggest that PAMP receptors are functionally coupled to G-proteins, although its signal transduction remains obscure. The present study also shows that amidation of C-terminal residue of PAMP is critical for receptor binding. The physiological function of PAMP remains undetermined.
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PMID:Specific binding sites for proadrenomedullin N-terminal 20 peptide (PAMP) in the rat. 877 Sep 30

Adrenomedullin is a novel hypotensive adrenal polypeptide originally isolated from a human pheochromocytoma and is structurally related to calcitonin gene-related peptide and islet amyloid polypeptide. Using immunocytochemistry, the occurrence of adrenomedullin in the adrenal gland and gastro-entero-pancreatic region in the rat was examined and its effect on insulin secretion from isolated rat islets was determined. Adrenomedullin-like immunoreactivity occurred in noradrenaline- and adrenaline-producing cells in the adrenal gland. Gastrointestinal endocrine cells, with increased density distally, displayed adrenomedullin-like immunoreactivity; these cells constituted a subpopulation of the enterochromaffin (serotonin-containing) cells. Co-localization of adrenomedullin with somatostatin, glicentin, gastrin/cholecystokinin, peptide YY or islet amyloid polypeptide was not encountered. Adrenomedullin-immunoreactive cells were not observed in the pancreatic islets. At 1, 10 and 100 nmol/l, adrenomedullin stimulated insulin release from isolated rat islets in the presence of 3.3 mmol/l glucose (P < 0.05) and at 100 nmol/l, the peptide potentiated insulin secretion also in the presence of 8.3 mmol/l glucose (P < 0.05). These findings suggest that, besides being an adrenal hypotensive peptide, adrenomedullin may be a gut hormone with a potential insulinotropic function.
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PMID:Adrenomedullin: localization in the gastrointestinal tract and effects on insulin secretion. 879 72

Adrenomedullin (AM) is a novel hypotensive peptide originally isolated from the pheochromocytoma tissue of humans. To examine the pathophysiological role of AM in primary aldosteronism (PA), the plasma concentration of AM in patients with PA was measured with a specific radioimmunoassay and compared to that in age- and sex-matched healthy normotensive subjects. In addition, the concentrations of AM as well as catecholamines in the plasma from both the adrenal vein and the inferior vena cava (IVC) were measured to determine whether or not the circulating AM in these PA patients is supplied from the adrenal medulla, which contains a much higher concentration of AM than any other human tissue does. The plasma concentration of AM in the PA patients (4.57 +/- 0.32 fmol/mL, n = 6) was significantly (P < .01) higher than that in the healthy subjects (3.06 +/- 0.20 fmol/mL, n = 12). A significant positive correlation (r = 0.62, P < .01) was observed between the mean blood pressure and the plasma AM level. The AM concentration in plasma from the adrenal vein was almost the same level as that from the IVC although the concentrations of both epinephrine and norepinephrine in the adrenal vein were much higher than those in the IVC. Therefore, it seems unlikely that the plasma AM in the PA patients is mainly supplied from the adrenal medulla. Judging from the potent hypotensive activity of AM, the present findings suggest that AM participates in defense mechanisms acting against the elevation of blood pressure in the patients with PA.
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PMID:Plasma adrenomedullin in patients with primary aldosteronism. 884 81

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

Adrenomedullin is a potent vasodilator peptide that was originally isolated from pheochromocytoma. The production and secretion of adrenomedullin by cultured choroid plexus carcinoma cells were studied by radioimmunoassay and northern blot hybridization. Choroid plexus carcinoma is a rare malignant tumor derived from the epithelium of the choroid plexus. Immunoreactive adrenomedullin was detected in the conditioned medium of choroid plexus carcinoma cells (40.8 +/- 7.5 fmol/10(5) cells/24 h; mean +/- SEM, n = 5). Reverse-phase HPLC of the conditioned medium showed one major peak of the immunoreactive peptide eluting in the position of synthetic human adrenomedullin and two smaller peaks eluting earlier. Addition of interleukin-1 beta (10 ng/ml) alone or in combination with three cytokines, interferon-gamma (100 U/ml), tumor necrosis factor-alpha (20 ng/ml), and interleukin-1 beta (10 ng/ml), caused significant increases in the immunoreactive adrenomedullin concentrations in the medium (approximately 175 and 293% of the control level, respectively). Northern blot analysis showed the expression of 1.6-kb adrenomedullin mRNA in the total RNA sample prepared from cultured choroid plexus carcinoma cells. Treatment with either interleukin-1 beta or the combination of three cytokines caused significant increases in levels of adrenomedullin mRNA in parallel with those in immunoreactive adrenomedullin concentrations in the conditioned medium. These findings raise a possibility that adrenomedullin is secreted from the choroid plexus and has physiological roles in the CNS via the CSF. In addition, adrenomedullin secreted from choroid plexus carcinoma may be related to the pathophysiology of the tumor.
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PMID:Production and secretion of adrenomedullin by cultured choroid plexus carcinoma cells. 900 63

Adrenomedullin is a potent vasodilator peptide that was isolated from human pheochromocytoma. We developed a sensitive and specific radioimmunoassay for adrenomedullin and studied the presence of adrenomedullin in human adrenal glands and adrenal tumors, including pheochromocytoma. High concentrations of immunoreactive adrenomedullin were found in normal parts of adrenal glands (cortex and medulla) (12.6 +/- 1.0 pmol/g wet wt, N = 7, mean +/- SEM). High concentrations of immunoreactive adrenomedullin were also present in the tumor tissues of pheochromocytoma (4.5 +/- 1.5 pmol/g wet wt, N = 11). Immunoreactive adrenomedullin was detected in some adrenocortical tumors, but these concentrations were much lower than those in the normal adrenal glands and pheochromocytomas. Reverse phase high-performance liquid chromatography of the normal adrenal gland and pheochromocytoma showed a peak eluting in the position of synthetic adrenomedullin 1-52. The present study has shown the presence of high concentrations of immunoreactive adrenomedullin in the normal adrenal glands and pheochromocytomas.
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PMID:Immunoreactive adrenomedullin in human adrenal glands and adrenal tumors. 904 63

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


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