title: Sex-specific effects of cardiovascular risk factors on endothelium-dependent dilation and endothelin activity in middle-aged women and men.
abstract: BACKGROUND
  Healthy middle-aged postmenopausal women have higher endothelium-dependent dilation and lower vasoconstrictor activity of endothelin-1 than men. Whether these sex-specific differences extend to patients with cardiovascular risk factors has not been investigated. The current study aimed to determine whether, in patients with cardiovascular risk factors, sex-specific differences exist in endothelium-dependent dilation and endothelin-1 activity.
  
  
  METHODS
  Forearm blood flow responses were measured by strain-gauge plethysmography during the intra-arterial infusion of acetylcholine, sodium nitroprusside, and the selective endothelin type A receptor blocker BQ-123 in 50 women and 64 men with cardiovascular risk factors.
  
  
  RESULTS
  Acetylcholine and sodium nitroprusside induced a significant vasodilation in women and men alike (p < 0.01 for both). Also BQ-123 caused a significant vasodilation (p < 0.001) in both groups. The vasodilator response to acetylcholine was greater in women compared to men; however there were no differences in the response to sodium nitroprusside and BQ-123 (p = NS for both) between the two sex groups.
  
  
  CONCLUSIONS
  Middle-aged women with cardiovascular risk factors have significantly higher endothelium-dependent dilation than middle-aged men; however, vascular endothelin 1 activity is similar in the two groups. These findings suggest that the presence of cardiovascular risk factors is associated with sex-specific effects on endothelium-dependent dilation but not on endothelin 1 activity. Further study is needed to confirm our findings and to characterize the mechanisms underlying this sex-specific regulation of endothelial function.
authors: MedStar Cardiovascular Research Network and MedStar Washington Hospital Center, Washington, District of Columbia, United States of America.
authors: Vijaywant
authors: V
authors: Brar
authors: Prince George's Hospital Center, Cheverly, Maryland, United States of America.
authors: Sartaj
authors: S
authors: Gill
authors: Internal Medicine, Catholic University, Rome, Italy.
authors: Carmine
authors: C
authors: Cardillo
authors: Systems Medicine, University of Tor Vergata, Rome, Italy.
authors: Manfredi
authors: M
authors: Tesauro
authors: Westchester Medical Center, Valhalla, New York, United States of America.
authors: Julio A
authors: JA
authors: Panza
authors: MedStar Cardiovascular Research Network and MedStar Washington Hospital Center, Washington, District of Columbia, United States of America.
authors: Umberto
authors: U
authors: Campia
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D002318:Cardiovascular Diseases / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology*; D065128:Endothelin Receptor Antagonists / Q000494:pharmacology; D019332:Endothelin-1 / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology*; D005260:Female; D005542:Forearm / Q000503:physiopathology; D006801:Humans; D007261:Infusions, Intra-Arterial / Q000379:methods; D008297:Male; D008875:Middle Aged; D009599:Nitroprusside / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects; D012307:Risk Factors; D012727:Sex Characteristics; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D010456:Peptides, Cyclic; D014665:Vasodilator Agents; D009599:Nitroprusside; D000109:Acetylcholine; C072247:cyclo(Trp-Asp-Pro-Val-Leu)