title: Lack of change in serum angiotensin-converting enzyme activity during the menstrual cycle.
abstract: BACKGROUND
  The Deletion (D) rather than Insertion (I) variant of the angiotensin-converting enzyme (ACE) gene is associated with higher circulating ACE activity. Meanwhile, coronary risk rises with the menstrual nadir in oestrogen levels, exogenous oestrogen reduces serum ACE activity (with a greater reduction the higher the baseline ACE activity), and pharmacological reduction in ACE activity is cardioprotective. Alterations in coronary risk associated with the menstrual cycle may thus be mediated through (genotype-dependent) changes in ACE activity. We have examined this hypothesis.
  
  
  METHODS
  Twenty-three healthy female subjects (12 II, 11 DD genotype) were studied. None were taking oral contraceptive agents. Blood was assayed for oestrogen, follicle stimulating hormone (FSH), luteinising hormone (LH), progesterone and ACE activity every three days throughout their menstrual cycle.
  
  
  RESULTS
  ACE activity was unrelated to oestrogen, FSH or LH during the menstrual cycle, irrespective of ACE genotype.
  
  
  CONCLUSIONS
  The increase in myocardial ischaemia during low oestrogen phases of the menstrual cycle does not appear mediated through a fall in serum ACE activity.
authors.affiliation: Rayne Institute, UCL Centre for Cardiovascular Genetics, 5 University Street, London, UK.
authors.forename: Julie
authors.initials: J
authors.lastname: Sanders
authors.forename: Joanna
authors.initials: J
authors.lastname: Harris
authors.forename: Jackie
authors.initials: J
authors.lastname: Cooper
authors.forename: Peter
authors.initials: P
authors.lastname: Gohlke
authors.forename: Steve E
authors.initials: SE
authors.lastname: Humphries
authors.forename: Hugh
authors.initials: H
authors.lastname: Montgomery
authors.forename: David R
authors.initials: DR
authors.lastname: Woods
mesh_terms: D000293:Adolescent; D000328:Adult; D004967:Estrogens / Q000097:blood*; D005260:Female; D005838:Genotype; D006801:Humans; D008597:Menstrual Cycle / Q000097:blood*; D007703:Peptidyl-Dipeptidase A / Q000097:blood*
chemical_list: D004967:Estrogens; D007703:Peptidyl-Dipeptidase A