Radioimmunoassay of atrial natriuretic polypeptide in heat-treated human plasma.

1987 ◽  
Vol 33 (5) ◽  
pp. 674-676 ◽  
Author(s):  
K Iinuma ◽  
I Ikeda ◽  
T Ogihara ◽  
H Hara ◽  
J Shima ◽  
...  

Abstract In this simple, sensitive radioimmunoassay (RIA) of atrial natriuretic polypeptide (hANP) in human plasma, nonspecific interference is minimized by deproteinizing the plasma by heat treatment at 85 degrees C for 10 min. We directly measure alpha-hANP in the supernates by RIA, with use of antiserum that recognizes the N-terminal region of alpha-hANP. The minimal detectable value was 0.4 pg per tube. The intra-assay CV was 6.6% (n = 8). The mean concentration of hANP in plasma of 54 healthy volunteers was 41 (SD 29) ng/L. Concentrations of hANP in plasma increased after saline infusion and high salt intake for one week in patients with essential hypertension. High concentrations were also measured in patients with renal failure and congestive heart failure. This method, which requires no extraction or purification with column chromatography, is especially useful for simultaneous measurement of several samples.

2001 ◽  
Vol 49 (10) ◽  
pp. 1293-1300 ◽  
Author(s):  
Gad M. Bialik ◽  
Zaid A. Abassi ◽  
Ilan Hammel ◽  
Joseph Winaver ◽  
Dina Lewinson

The natriuretic peptides are believed to play an important role in the pathophysiology of congestive heart failure (CHF). We utilized a quantitative cytomorphometric method, using double immunocytochemical labeling, to assess the characteristics of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in atrial granules in an experimental model of rats with CHF induced by aortocaval fistula. Rats with CHF were further divided into decompensated (sodium-retaining) and compensated (sodium-excreting) subgroups and compared with a sham-operated control group. A total of 947 granules in myocytes in the right atrium were analyzed, using electron microscopy and a computerized analysis system. Decompensated CHF was associated with alterations in the modal nature of granule content packing, as depicted by moving bin analysis, and in the granule density of both peptides. In control rats, the mean density of gold particles attached to both peptides was 347.0 ± 103.6 and 306.3 ± 89.9 gold particles/μm2 for ANP and BNP, respectively. Similar mean density was revealed in the compensated rats (390.6 ± 81.0 and 351.3 ± 62.1 gold particles/μm2 for ANP and BNP, respectively). However, in rats with decompensated CHF, a significant decrease in the mean density of gold particles was observed (141.6 ± 67.3 and 158.0 ± 71.2 gold particles/μm2 for ANP and BNP, respectively; p < 0.05 compared with compensated rats, for both ANP and BNP). The ANP:BNP ratio did not differ between groups. These findings indicate that the development of decompensated CHF in rats with aortocaval fistula is associated with a marked decrease in the density of both peptides in atrial granules, as well as in alterations in the quantal nature of granule formation. The data further suggest that both peptides, ANP and BNP, may be regulated in the atrium by a common secretory mechanism in CHF.


Blood ◽  
1990 ◽  
Vol 75 (1) ◽  
pp. 102-107 ◽  
Author(s):  
HA Huebers ◽  
Y Beguin ◽  
P Pootrakul ◽  
D Einspahr ◽  
CA Finch

Abstract Intact transferrin receptor molecules complexed with transferrin were found in human plasma. The concentration of receptors was determined by an enzyme-linked immunosorbent assay that uses polyclonal antibodies. The mean concentration of 8,279 micrograms/L in 56 normal adults appears to be unrelated to age or sex. Additional receptor measurements were performed on plasmas from 260 subjects with erythropoietic disorders. Decreased concentration of plasma receptors was found in patients with erythroid hypoplasia and increased numbers in those with erythroid hyperplasia. Ferrokinetic measurements of erythropoiesis were compared with numbers of receptors in 148 subjects, and a close correlation was found (r = .86). Both sets of values, measured in different conditions and expressed in relation to normal, were consistent with expected values. Receptor values were unproportionally increased only in conditions of iron deficiency. It is concluded that plasma receptors have a constant relationship to tissue receptors, and their number in most instances reflects the rate of erythropoiesis.


Peptides ◽  
1990 ◽  
Vol 11 (3) ◽  
pp. 501-506
Author(s):  
Jiri Widimsky ◽  
Waldemar Debinski ◽  
Otto Kuchel ◽  
Nguyen T. Buu ◽  
Patrick Du Souich

1971 ◽  
Vol 51 (1) ◽  
pp. 193-200 ◽  
Author(s):  
J. E. MILTIMORE ◽  
J. L. MASON

Molybdenum and Cu concentrations and Cu/Mo ratios were determined on samples of legume hay, grass legume hay, grass hay, sedge hay, oat forage, corn silage and grains throughout British Columbia. In addition, the relationships between Cu distribution and both Mo concentration and the Cu/Mo ratio were determined for all feeds. The critical Cu/Mo ratio was selected as 2.0, and samples with ratios below 2.0 would be expected to cause conditioned copper deficiency. Sedge hays had a mean Cu/Mo ratio of 2.1, which was less than half the mean ratio of 4.4 for grass hays. The mean ratios for the other classes of feed were 5.0 or higher. Notwithstanding the favorable mean ratios, 19% of all samples had ratios below 2.0. The lowest Cu/Mo ratio was 0.1 and the highest was 52.7, which shows extreme variability. Molybdenum concentrations were generally low, with 35% of all samples below 1 ppm Mo. There were no unusually high Mo concentrations, as only 1% of all feeds were above 8.0 ppm Mo and the highest value was 9.9 ppm. Copper concentrations were low. Fourteen percent of all samples were below 3.0 ppm and 95% of all samples were below 10.0 ppm. Legume feeds had a mean Cu concentration of 7.5 ppm, in contrast to sedge hays which had a mean concentration of 3.3 ppm Cu. As Cu concentrations increased in all feeds the Cu/Mo ratios also increased, when all feeds were considered in one compilation. Molybdenum concentrations were high, then decreased, but increased to the same high concentrations as Cu concentrations increased. These data indicate an unexpectedly high and nutritionally important variability in Cu/Mo ratios, and add further support to our previous report of extensive low levels of Cu. Both Cu and Mo analyses are required to predict the need for Cu supplementation. This appears to be the first extensive report on Cu/Mo ratios in feeds.


Peptides ◽  
1986 ◽  
Vol 7 (1) ◽  
pp. 141-145 ◽  
Author(s):  
M. Naruse ◽  
K. Naruse ◽  
K. Obana ◽  
F. Kurimoto ◽  
H. Sakurai ◽  
...  

2015 ◽  
Vol 308 (5) ◽  
pp. H530-H539 ◽  
Author(s):  
Koji Ito ◽  
Yoshitaka Hirooka ◽  
Kenji Sunagawa

The cardiac sympathetic afferent (CSA), which plays an important role in heart-brain communication for sympathoexcitation, is stimulated in heart failure. Additionally, high salt intake leads to further sympathoexcitation due to activation of hypothalamic epithelial Na+ channels (ENaCs) in heart failure. In the present study, we stimulated the CSA in adult male mice by epicardial application of capsaicin and using ethanol as a control to determine whether CSA stimulation led to activation of hypothalamic ENaCs, resulting in salt-induced sympathoexcitation. Three days after capsaicin treatment, an upregulation of hypothalamic α-ENaCs, without activation of mineralocorticoid receptors, was observed. We also examined expression levels of the known ENaC activator TNF-α. Hypothalamic TNF-α increased in capsaicin-treated mice, whereas intracerebroventricular infusion of the TNF-α blocker etanercept prevented capsaicin-induced upregulation of α-ENaCs. To examine brain arterial pressure (AP) sensitivity toward Na+, we performed an intracerebroventricular infusion of high Na+-containing (0.2 M) artificial cerebrospinal fluid. AP and heart rate were significantly increased in capsaicin-treated mice compared with control mice. CSA stimulation also caused excitatory responses with high salt intake. Compared with a regular salt diet, the high-salt diet augmented AP, heart rate, and 24-h urinary norepinephrine excretion, which is an indirect marker of sympathetic activity with mineralocorticoid receptor activation, in capsaicin-treated mice but not in ethanol-treated mice. Treatment with etanercept or the ENaC blocker benzamil prevented these salt-induced excitatory responses. In summary, we show that CSA stimulation leads to an upregulation of hypothalamic α-ENaCs mediated via an increase in TNF-α and results in increased salt sensitivity.


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