title: Effects of estrogen replacement therapy on natriuretic peptides and blood pressure.
abstract: OBJECTIVE
  Estrogen replacement therapy (ERT) has been reported to affect blood pressure. Since natriuretic peptides have natriuretic and vasodilatory activity and also inhibit the renin-angiotensin-aldosterone system and lower blood pressure, it was hypothesized that the changes in blood pressure effected by ERT might be mediated via changes in natriuretic peptides.
  
  
  METHODS
  Fifty-eight postmenopausal hysterectomized women were randomized in a double-blind, double-dummy study to receive either peroral estradiol valerate 2 mg/day or transdermal estradiol gel containing 1 mg estradiol/day for 6 months. Blood pressure was measured by using an automatic, oscillometric device. Plasma atrial natriuretic peptide (ANP), N-terminal fragment of proANP (NT-proANP), B-type natriuretic peptide (BNP), aldosterone, and renin were determined by radioimmunoassay.
  
  
  RESULTS
  The mean decrease in diastolic blood pressure was -6 mmHg both in the peroral group (n = 26) (P = 0.002) and in the gel group (n = 27) (P = 0.001), and the corresponding decreases in systolic blood pressure were -4 mmHg (P = 0.070) and -7 mmHg (P = 0.028) in the sitting position. Plasma NT-proANP rose from 212 to 264 pmol/l (P = 0.001) on peroral ERT and from 240 to 292 pmol/l (P = 0.008) on transdermal ERT. No significant changes were observed in the plasma ANP, BNP, aldosterone, and renin levels.
  
  
  CONCLUSIONS
  Both peroral and transdermal ERT result in elevated plasma levels of NT-proANP, indicating an activation of the natriuretic peptide system. This could explain, at least in part, the lowering of blood pressure during ERT.
authors.affiliation: Department of Internal Medicine, Biocenter Oulu, University of Oulu, P.O. Box 20, 90029 OYS, Oulu, Finland. ahkarjal@cc.oulu.fi
authors.forename: Anna H
authors.initials: AH
authors.lastname: Karjalainen
authors.forename: Heikki
authors.initials: H
authors.lastname: Ruskoaho
authors.forename: Olli
authors.initials: O
authors.lastname: Vuolteenaho
authors.forename: Jorma E
authors.initials: JE
authors.lastname: Heikkinen
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: Bäckström
authors.forename: Markku J
authors.initials: MJ
authors.lastname: Savolainen
authors.forename: Y Antero
authors.initials: YA
authors.lastname: Kesäniemi
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000450:Aldosterone / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects*; D004311:Double-Blind Method; D004958:Estradiol / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000494:pharmacology; D015914:Estrogen Replacement Therapy / Q000379:methods; D005260:Female; D006801:Humans; D008875:Middle Aged; D045265:Natriuretic Peptides / Q000097:blood*; D012083:Renin / Q000097:blood
chemical_list: D045265:Natriuretic Peptides; D000450:Aldosterone; D004958:Estradiol; D012083:Renin