title: Mechanical properties of human saphenous veins from normotensive and hypertensive patients.
abstract: BACKGROUND
  Different reactivities of saphenous vein grafts in hypertensive and normotensive patients could lead to differences in the postoperative patency of the grafts.
  
  
  METHODS
  In saphenous vein rings isolated from remnants of aorta-coronary grafts obtained from hypertensive and normotensive patients we studied the length-tension relationship; response to high levels of potassium, norepinephrine, and epinephrine; and relaxation in response to calcium deprivation.
  
  
  RESULTS
  The rings from hypertensive patients were stiffer and developed more force (grams force/grams weight) than the rings from normotensive subjects to 80 mmol/L potassium (59+/-16 versus 25+/-5, p < 0.05) and to 1 micromol/L norepinephrine (61+/-8 versus 36+/-7, p < 0.05), but not to 10 micromol/L epinephrine (57+/-11 and 54+/-11; not significant). The rings from hypertensive patients relaxed more slowly than those of the normotensive subjects in a calcium-free medium (time to half-relaxation of 976+/-180 versus 548+/-81 seconds; p < 0.05).
  
  
  CONCLUSIONS
  The saphenous vein from hypertensive patients is less distensible, slower to relax, and more reactive to at least two agonists. These differences could influence the graft's patency and the clinical outcome.
authors.affiliation: Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina.
authors.forename: V
authors.initials: V
authors.lastname: Milesi
authors.forename: A
authors.initials: A
authors.lastname: Rebolledo
authors.forename: F
authors.initials: F
authors.lastname: Ayala Paredes
authors.forename: N
authors.initials: N
authors.lastname: Sanz
authors.forename: J
authors.initials: J
authors.lastname: Tommasi
authors.forename: G J
authors.initials: GJ
authors.lastname: Rinaldi
authors.forename: A O
authors.initials: AO
authors.lastname: Grassi
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002118:Calcium / Q000502:physiology; D004837:Epinephrine / Q000494:pharmacology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D066298:In Vitro Techniques; D008875:Middle Aged; D009638:Norepinephrine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D012501:Saphenous Vein / Q000187:drug effects / Q000503:physiopathology*; D014654:Vascular Patency
chemical_list: D011188:Potassium; D002118:Calcium; D009638:Norepinephrine; D004837:Epinephrine