Binding sites for atrial natriuretic peptide on platelets in patients with congestive cardiomyopathy.
The aim of the present investigation was to evaluate a possible down-regulation of atrial natriuretic peptide (ANP) binding sites on platelets in patients with chronically elevated ANP plasma levels. The assay procedure was proved to be able to measure the total number of binding sites even in the presence of high ANP plasma levels. We studied 15 adult patients with congestive cardiomyopathy in comparison to 18 healthy volunteers. In the patients the median ANP plasma level (median = 375, range: 155-900 pg ml-1) was about six-fold higher than in the healthy volunteers (median: 55.5, range: 20-90 pg ml-1). The median cyclic guanosine monophosphate (cGMP) plasma level (median: 6.2, range: 2.5-21.4 pmol ml-1) was about three-fold higher than in the healthy volunteers (median: 1.8 range: 1-2.8 pmol ml-1). Despite these markedly elevated ANP and cGMP plasma levels we did not find significantly less receptors per platelet in the patients (median: 19, range: 7.2-60.2) than in the healthy volunteers (median: 24.5, range: 14.8-41.1). Furthermore, there was no difference in the dissociation constants between the patients (median: 10.5, range: 7.9-27.4 pmol l-1) and the control subjects (median: 8.9, range: 5.4-17 pmol l-1).
Strom
T M
TM
Department of Paediatrics, Technical University of Munich, FRG.
Weil
J
J
Braun
F
F
Stangl
K
K
Timnik
A
A
Heim
J M
JM
Gerzer
R
R
D000368:Aged; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D001665:Binding Sites; D001792:Blood Platelets / Q000378:metabolism*; D002311:Cardiomyopathy, Dilated / Q000378:metabolism*; D006152:Cyclic GMP / Q000097:blood; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D013997:Time Factors
D007457:Iodine Radioisotopes; D009320:Atrial Natriuretic Factor; D006152:Cyclic GMP