title: Endothelin and effects of endothelin-receptor activation in the mammary and radial artery.
abstract: OBJECTIVE
  To determine the tissue content and endothelin-receptor characteristics of endothelin-1 in the radial artery in relation to the internal mammary artery.
  
  
  METHODS
  Endothelin-1 content was quantified in the radial artery and the internal mammary artery. Both arteries were exposed to endothelin-1 and agonists of the endothelin A and B receptors.
  
  
  RESULTS
  The highest level of endothelin-1 was found in the radial artery. Endothelin-1 contracted both arteries. The contraction was sensitive to endothelinA-receptor agonism and enhanced in both arteries by inhibition of prostacyclin and nitric oxide formation. In the internal mammary artery the endothelinB-receptor agonist caused an endothelinA-receptor sensitive contraction augmented by inhibition of nitric oxide and prostacyclin. However, in the radial artery this contraction was only observed in the presence of inhibition of nitric oxide and prostaglandin.
  
  
  CONCLUSIONS
  The highest endothelin-1 content was found in the radial artery. The functional effects of endothelin-1 in the radial artery were similar to that in the internal mammary artery, mediated by predominantly endothelinA-receptor activation causing vasoconstriction. Selective endothelinA-receptor blockade may prove beneficial in preventing graft spasm in the radial as well as the internal mammary artery.
authors.affiliation: Department of Thoracic Surgery, Karolinska Hospital, Stockholm, Sweden. ulf.lockowandt@ks.se
authors.forename: Ulf
authors.initials: U
authors.lastname: Lockowandt
authors.forename: Andrew
authors.initials: A
authors.lastname: Ritchie
authors.forename: Michael
authors.initials: M
authors.lastname: Grossebener
authors.forename: Anders
authors.initials: A
authors.lastname: Franco-Cereceda
mesh_terms: D015415:Biomarkers / Q000032:analysis; D001026:Coronary Artery Bypass / Q000379:methods; D003327:Coronary Disease / Q000000981:diagnostic imaging; D019332:Endothelin-1 / Q000032:analysis / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008323:Mammary Arteries / Q000187:drug effects / Q000378:metabolism*; D017534:Radial Artery / Q000187:drug effects / Q000378:metabolism*; D044022:Receptor, Endothelin A / Q000032:analysis / Q000378:metabolism*; D044023:Receptor, Endothelin B / Q000032:analysis / Q000378:metabolism*; D012680:Sensitivity and Specificity; D046509:Tissue Culture Techniques; D014463:Ultrasonography
chemical_list: D015415:Biomarkers; D019332:Endothelin-1; D044022:Receptor, Endothelin A; D044023:Receptor, Endothelin B; D007213:Indomethacin