The N-terminal and C-terminal portions of the atrial natriuretic factor prohormone increase during preeclampsia.
The influence of preeclampsia on the circulating concentrations of the 28-amino-acid carboxy terminus (C-terminus) (i.e., atrial natriuretic factor) and the amino terminus (N-terminus) of the 126-amino-acid atrial natriuretic factor prohormone (pro ANF) was studied in the third trimester with the use of three specific radioimmunoassays that recognize: (1) atrial natriuretic factor (i.e., amino acids 99 to 126), (2) the whole 98-amino-acid N-terminus, and (3) amino acids 31 to 67 from the midportion of the N-terminus of the prohormone. The C-terminus was significantly increased (p less than 0.001) in the third trimester in women with preeclampsia, the mean +/- SEM of 15 subjects was 150 +/- 7 pg/ml versus 89 +/- 7 pg/ml in the third trimester in 12 women during normal pregnancies and 65 +/- 2 pg/ml in 19 healthy nonpregnant women. The whole 98-amino-acid N-terminus, likewise, was significantly increased (p less than 0.001) in women with preeclampsia to 4706 +/- 629 pg/ml versus 2160 +/- 79 pg/ml in women in the third trimester of normal pregnancies and versus the circulating concentration of 1847 +/- 127 pg/ml in healthy nonpregnant women. ProANF 31 to 67 mean circulating concentration in preeclampsia was 4638 +/- 725 pg/ml, which was also significantly (p less than 0.001) increased compared with its mean circulating concentration in the third trimester of normal pregnancy of 1758 +/- 83 pg/ml or that in healthy nonpregnant women (1400 +/- 105 pg/ml). The circulating concentrations of both the N-terminus and C-terminus of the atrial natriuretic factor prohormone decreased within 24 hours after delivery in contrast to a normal pregnancy in which they both increase post partum. These results indicate a marked difference in the metabolism of both the N-terminus and the C-terminus of the atrial natriuretic factor prohormone in women with preeclampsia versus that in women with normal pregnancies or that in healthy nonpregnant women.
Merkouris
R W
RW
Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock 72205.
Miller
F C
FC
Catanzarite
V
V
Quirk
J G
JG
Rigg
L A
LA
Vesely
D L
DL
D000293:Adolescent; D000328:Adult; D009320:Atrial Natriuretic Factor / Q000097:blood*; D005260:Female; D006801:Humans; D010446:Peptide Fragments / Q000097:blood; D049590:Postpartum Period / Q000378:metabolism; D011225:Pre-Eclampsia / Q000378:metabolism*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011498:Protein Precursors / Q000097:blood*; D011863:Radioimmunoassay
D010446:Peptide Fragments; D011498:Protein Precursors; C054547:atrial natriuretic factor prohormone (1-30), human; C054548:atrial natriuretic factor prohormone (31-67); D009320:Atrial Natriuretic Factor