Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study reports about novel findings concerning the interrelationship between release of human atrial natriuretic factor (hANP) and the clinical situation of patients suffering from congestive heart failure. Estimations of plasma hANP were done by specific and sensitive extraction-based RIA. The normal range was 5 to 80 ng/l, mean +/- SEM = 30 +/- 15 ng/l, n = 106. Influence of response to therapy on hANP-release was studied in altogether 14 patients. 12 of these patients had elevated plasma hANP at admittance, surprisingly peptide levels were normal in 2 patients throughout the study. 9 out of the 14 patients responded well to therapy (shift from NYHA IV/III to NYHA II within about 10 days), hANP-levels decreased to normal values: 235 +/- 104 ng/l vs. 65 +/- 13 ng/l; p less than 0.001. The 5 residual patients responded to therapy only partially (shift from HYHA IV to NYHA III within an observation interval of about 2 weeks). Plasma hANP values decreased from 225 +/- 94 ng/l to 137 +/- 22 ng/l (p less than 0.02), but were still supranormal. Atrial fibrillation, which persisted in 8 out of the 14 patients after therapy did not influence hANP levels: hANP levels paralleled clinical signs of improvement, irrespective of atrial fibrillation. Right heart catheterization revealed very high mean right atrial pressures in those 2 patients mentioned above, who had normal pretherapeutic hANP.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interpretation of plasma concentrations of human atrial natriuretic peptide (hANP) in congestive heart failure. 214 87

1. To investigate the mechanisms leading to enhanced synthesis and release of atrial natriuretic factor during chronic hypoxia, we measured immunoreactive plasma atrial natriuretic factor, blood gases, packed cell volume, pulmonary artery pressure and systemic artery pressure in male Sprague-Dawley rats exposed to 1, 2 or 3 weeks of normobaric hypoxia. Rats were implanted with pulmonary and carotid artery catheters and studied conscious, 23 h after return to hypoxia. 2. The concentration of atrial natriuretic factor messenger RNA was measured in the right and left ventricular free walls of rats exposed to 3 weeks of hypoxia and in normoxic control rats. 3. There was a trend for plasma atrial natriuretic factor to increase with the duration of exposure to hypoxia but only the 3-week hypoxic rats had a significantly higher level (1080 +/- 193 pg/ml) than the normoxic control rats (318 +/- 46 pg/ml, P less than 0.05, mean +/- SEM). When all the data from normoxic and hypoxic rats were considered together, plasma atrial natriuretic factor was positively correlated with packed cell volume (r = 0.66, P less than 0.001), pulmonary artery pressure (r = 0.68, P less than 0.002), and the index of right ventricular hypertrophy (r = 0.54, P less than 0.01), but after analysis of partial correlation, packed cell volume was the only independent contributing factor to the variance in the level of plasma atrial natriuretic factor (r2 = 0.24).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Synthesis and secretion of atrial natriuretic factor during chronic hypoxia: a study in the conscious instrumented rat. 216 93

1. Asthmatic patients bronchodilate in response to infused atrial natriuretic factor. We wished to determine whether the airways of normal subjects responded in a similar way. 2. Changes in airway resistance, as determined by specific airway conductance, were measured in eight normal subjects in response to intravenous infusion of atrial natriuretic factor at doses of 0.5, 2 and 10 pmol min-1 kg-1. 3. No significant effect was observed on specific airway conductance at any rate of infusion despite maximum mean (SEM) plasma levels of 597 (62) pg of atrial natriuretic factor/ml in peripheral venous blood. 4. A second study was performed using six of the eight original subjects and employing a pharmacological dose of 50 pmol of atrial natriuretic factor min-1 kg-1. This produced mean plasma levels of 2056 pg/ml and a mean increase of 31% in specific airway conductance. 5. It is concluded that pharmacological, but not pathophysiological, elevations of plasma atrial natriuretic factor may significantly alter bronchomotor tone in normal subjects.
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PMID:Effect of atrial natriuretic factor on bronchomotor tone in the normal human airway. 216 91

In a search for factors contributing to the sustained blood pressure (BP) elevation in acutely volume-loaded animals, dextran dissolved in lactated Ringer's solution (20 ml/kg) was infused into 34 mongrel dogs over a period of 1 hour under pentobarbital anesthesia and changes in hemodynamic and humoral variables were monitored during its infusion and for 3 hours after its infusion. BP elevation during volume loading (from 114 +/- 3 to 128 +/- 3 [SEM] mm Hg) was attributed to an increase in cardiac output. After volume loading, some dogs maintained BP elevation whereas others did not. The former group showed an increase in total peripheral resistance, demonstrating a transformation of cardiac output to total peripheral resistance as a responsible factor in maintenance of the elevated BP. The plasma levels of norepinephrine, vasopressin, and plasma renin activity were not elevated, indicating that these vasoactive factors were not responsible for elevation of the BP or total peripheral resistance. The changes in the hematocrit, atrial natriuretic factor, urine volume, and urinary sodium excretion were identical in the two groups, and natriuresis was not prominent when total peripheral resistance was high. Pressor responses to norepinephrine and angiotensin II were potentiated 3 hours after stopping infusion in both groups, but this potentiation was not correlated with the increase in total peripheral resistance or mean BP. Thus, acute volume expansion produced resistance-dependent hypertension following the initial volume-dependent hypertension. It is unlikely that a vascular sensitizing natriuretic factor plays a role in the resistance-dependent BP elevation. The mechanism and physiological importance of hypersensitivity to vasoactive substances remain to be elucidated.
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PMID:Vasoconstriction and hypersensitivity to vasoactive substances after acute volume expansion in dogs. 245 68

The effect of calcium on plasma atrial natriuretic factor (ANF) concentration was determined in spontaneously hypertensive rats (SHR) and their control, Wistar-Kyoto (WKY) rats. CaCl2 10.5 mg (0.095 mmol) in 0.54 ml 5% glucose or an equal volume of vehicle alone was infused intravenously for 30 minutes into conscious precannulated SHR (vehicle, n = 16; CaCl2, n = 16) and WKY rats (vehicle, n = 25; CaCl2, n = 15). Direct systolic blood pressure was measured throughout the infusion period. Blood samples for serum total calcium and plasma ANF were obtained at the end of each experiment. The systolic blood pressure did not change significantly during infusion of the vehicle or CaCl2 in either strain. No significant difference was observed in serum total calcium concentration between SHR and WKY rats after vehicle (9.8 +/- 0.1 [mean +/- SEM] mg/dl vs. 10.0 +/- 0.1) or after CaCl2 infusion (12.2 +/- 0.3 vs. 12.2 +/- 0.2). Plasma ANF concentrations after both vehicle and CaCl2 infusion were significantly higher in SHR than in WKY rats (vehicle, 211 +/- 24 pg/ml vs. 129 +/- 11, p less than 0.05; CaCl2, 395 +/- 21 vs. 278 +/- 33, p less than 0.05). There were high degrees of correlation between serum total calcium and plasma ANF both in SHR (r = 0.77, p less than 0.001) and in WKY rats (r = 0.76, p less than 0.001). No significant difference was observed in the slopes of the regression lines of ANF as a function of the serum total calcium concentration between SHR and WKY rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Calcium infusion increases plasma atrial natriuretic factor in spontaneously hypertensive rats. 252 28

The purpose of this study was to measure the effect of enhanced venous return on atrial natriuretic factor (ANF) secretion during exercise and upright posture and the consequences on renin angiotensin aldosterone system (RAAS) activity. Six healthy male subjects were submitted to four different procedures. All procedures were performed in the same position, i.e. riding on a support with legs hanging. Two procedures were performed at rest: the subjects were studied after a 25-min rest in this position, with and without the lower limb fitted with an anti-G suit inflated to 60 mmHg. Two procedures were carried out with physical exercise; arm-cranking was performed in the same position with and without the anti-G suit inflated to 60 mmHg. Venous blood was collected before and after each procedure in order to measure plasma ANF, plasma aldosterone concentration (PAC), plasma renin activity (PRA), corticotrophin (ACTH) and catecholamine level. The data mean +/- SEM showed that the ANF plasma level decreased significantly (p less than 0.05) from 32.5 +/- 4 to 28 +/- 6 pg.ml-1 after a 20-min rest in the upright posture, whereas this effect was absolished with anti-G suit inflation. Physical exercise with and without the anti-G suit increased the ANF level above control values (60 +/- 13.6 pg.ml-1 and 53 +/- 13 pg.ml-1): anti-G suit inflation had no significant effect. PRA increased after rest in an upright posture and during physical exercise; anti-G suit inflation abolished this increase in both conditions.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of physical exercise and anti-G suit inflation on atrial natriuretic factor plasma level. 252 53

Two peptides consisting of amino acids 1-30 and 31-67 of the N-terminus of the prohormone of atrial natriuretic factor (pro-ANF) that have vasodilatory and natriuretic properties were investigated to determine if they circulate in humans. Specific and sensitive radioimmunoassays were developed to amino acids 1-30, 31-67, and 99-126 of pro-ANF. Evaluation of human plasma that had been subjected to reverse-phase high-pressure liquid chromatography suggested that pro-ANFs 1-30 and 31-67 as well as ANF were distinct peaks in human plasma corresponding exactly to pure synthetic peaks of these peptides on high-pressure liquid chromatography. Molecular weight determination of the endogenous immunoreactive peptides measured in plasma by G-50 Sephadex gel permeation chromatography revealed that the pro-ANF 1-30 radioimmunoassay recognized a peptide of 10,000 MW, which is consistent with it measuring the whole N-terminus of pro-ANF (amino acids 1-98) but without ANF (C-terminus) attached to it. The pro-ANF 31-67 radioimmunoassay recognized mainly (more than 95%) a peptide of 3,900-4,000 MW, which corresponds closely with its actual molecular weight of 3,878. Our ANF radioimmunoassay recognizes a peptide in plasma of 3,000 MW with the known molecular weight of ANF being 3,081. The mean circulating concentrations of immunoreactive pro-ANF 1-98, pro-ANF 31-67, and ANF in 54 control subjects were 531 +/- 25, 371 +/- 18, and 22 +/- 1 fmol/ml (+/- SEM), respectively. Thirty patients with varying severity of congestive heart failure were also studied. The N-terminus, C-terminus, and pro-ANF 31-67 increased: twofold for New York Heart Association functional Class II, threefold to ninefold for Class III, and 10- to 20-fold for Class IV patients with congestive heart failure. Thus, the N-terminus and a 4,000-MW peptide from the midportion of the N-terminus of pro-ANF as well as ANF circulate normally and increased proportionately to the increasing severity of congestive heart failure. However, because the pro-ANF 31-67 radioimmunoassay was the only assay that discriminated between patients with Class I congestive heart failure and control subjects, this assay may be the most useful to accurately classify the severity of congestive heart failure.
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PMID:The N-terminus and a 4,000-MW peptide from the midportion of the N-terminus of the atrial natriuretic factor prohormone each circulate in humans and increase in congestive heart failure. 252 42

1. To investigate atrial natriuretic factor (ANF) and its relationship to the renin system in diabetes, we measured plasma immunoreactive ANF and plasma renin activity (PRA) in 27 non-ketotic diabetic patients without evidence of cardiac or overt renal disease, and compared them with 26 age- and sex-matched normal subjects. 2. Diabetic patients were divided prospectively into poor (PGC, n = 14) or moderate (MGC, n = 13) glycaemic control depending on their concurrent plasma glycohaemoglobin (HbA1) levels (greater than 9% or less than 9%, respectively). Plasma ANF was elevated in PGC diabetic patients (15.7 +/- 1.8 fmol/ml, mean +/- SEM) compared with MGC diabetics (9.9 +/- 0.8 fmol/ml, P less than 0.001) and normal subjects (10.1 +/- 1.3 fmol/ml, P less than 0.05). 3. In contrast, PRA was lower in the PGC diabetic patients (1.3 +/- 0.3 pmol of angiotensin 1 h-1 ml-1) compared with the other groups (2.5 +/- 0.5 and 2.1 +/- 0.2 pmol of angiotensin I h-1 ml-1, P less than 0.05). Diabetic groups had proportionally more patients with high prorenin values (over 30 ng h-1 ml-1) than the normal group, but there was no difference between the diabetic groups. 4. Among the diabetic patients, ANF was directly related to HbA1 (r = 0.49, P less than 0.005) and urinary albumin excretion (r = 0.40, P less than 0.02), and was inversely related to PRA (r = 0.36, P less than 0.04) and plasma creatinine (r = -0.42, P less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Increased plasma atrial natriuretic factor and reduced plasma renin in patients with poorly controlled diabetes mellitus. 252 63

To ascertain whether small shifts in plasma atrial natriuretic factor (ANF) exerted biological effects in hypertension, we studied the renal, hemodynamic, and hormonal effects of ANF [human ANF-(99-126)] infused at a dose (0.75 pmol/kg/min for 3 hours) that would induce changes in plasma ANF confined to the normal, resting range, in a group of six young men with uncomplicated, mild essential hypertension. During ANF infusions, the patients excreted 11.8 +/- 2.0 mmol (mean +/- SEM) sodium more than during the time-matched placebo phase natriuresis (p less than 0.001, mean increase of 53% above placebo values). Urinary excretion of cyclic guanosine monophosphate rose to more than double (212%, p less than 0.001) placebo values. Plasma renin activity (0.4 +/- 0.05 vs. 0.9 +/- 0.12 nmol/l/hr, p less than 0.0001) and aldosterone concentrations (102 +/- 4 vs. 184 +/- 47 pmol/l, p less than 0.05) were clearly suppressed during administration of ANF. Plasma norepinephrine also fell significantly below placebo values (268 +/- 17 vs. 439 +/- 35 pg/ml, p less than 0.05). Urine volume, the excretion of electrolytes other than sodium, hematocrit, effective renal plasma flow, glomerular filtration rate, and filtration fraction were unaffected by ANF. Similarly, plasma concentrations of epinephrine, arginine vasopressin, adrenocorticotropic hormone, and cortisol were unchanged. Blood pressure and heart rate were unchanged. Minor perturbations in plasma ANF concentrations exert clear biological effects in patients with mild essential hypertension. These data suggest that such minor shifts in plasma ANF are of physiological relevance in mild hypertension and probably contribute to volume homeostasis in this condition.
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PMID:Atrial natriuretic factor in hypertension: bioactivity at normal plasma levels. 252 19

The relationships between plasma atrial natriuretic factor (ANF), blood pressure (BP) and age have not been clearly defined. We measured plasma ANF levels and BP in 128 normal subjects (65 male; 63 female; mean age 48 years, range 20-87 years) on no medication. In subjects of 75 years or less (n = 120) plasma ANF was 5.7 +/- 0.3 pmol/l (mean +/- SEM). Plasma ANF did not differ between sexes (males 5.6 +/- 0.4 pmol/l, females 5.9 +/- 0.4 pmol/l). There was a positive correlation between plasma ANF and age, correlation coefficient (r) = 0.46, systolic BP (r = 0.44), diastolic BP (r = 0.22) and mean BP (r = 0.37) (all P less than 0.01), but after multiple linear regression analysis plasma ANF only related significantly (P less than 0.01) to age and systolic BP once other factors had been excluded. We also measured plasma ANF after erect and supine posture and during a 21IV normal saline infusion given over 4 hrs (n = 24; age range 21-62 years) after an overnight fast. Mean plasma ANF was 5.9 +/- 1.1 pmol/l erect, 7.4 +/- 1.6 pmol/l supine and rose to 10.1 +/- 1.4 pmol/l after saline (both P less than 0.05 vs basal). Response to saline was assessed as the area under the curve of hourly measurements. Neither this nor peak ANF during saline infusion correlated with age. We conclude that basal plasma ANF is influenced by age and systolic BP but plasma ANF response to acute saline stimulation is not.
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PMID:Relationship between basal and sodium-stimulated plasma atrial natriuretic factor, age, sex and blood pressure in normal man. 252 92


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