title: Coronary vasodilation by nitrates is not mediated by the prostaglandin system: a quantitative cineangiographic study.
abstract: The possible role of prostaglandins in mediating large coronary artery vasodilation by nitrates was investigated by quantitative magnification coronary angiography. The effects of aspirin (1 g systemically and 100 mg intracoronary) in preventing large coronary artery vasodilation induced by intracoronary isosorbide dinitrate was investigated in 16 patients. Of these, 5 received 0.3 mg (Group 1A) and 11 received 3 mg (Group 1B) intracoronary isosorbide dinitrate, before and 15 minutes after aspirin. Relative to control, 0.3 mg isosorbide dinitrate induced a 19 +/- 9% (mean +/- SD) (p less than 0.01) and 19.5 +/- 11% (p less than 0.01) increase in coronary diameter before and after aspirin, respectively (p = NS). Changes after 3 mg isosorbide were 23 +/- 12% (p less than 0.01) and 26.5 +/- 14% (p less than 0.01), respectively, before and after aspirin (p = NS). In 10 additional patients (Group 2), the effect of the same dose of aspirin on rest coronary artery tone was assessed: changes relative to control were 0.9 +/- 5.5% (p = NS) minutes after aspirin. The intracoronary administration of 3 mg isosorbide dinitrate produced a 24.7 +/- 11% increase in coronary diameter (p = NS versus pre- and postaspirin isosorbide in Group 1B). Urinary 6-ketoprostaglandin-F1 alpha values in urine samples collected in the 8 hours before and the 8 hours after the study in five patients in Group 1B and five patients of Group 2, revealed a 36 +/- 14% (mean +/- SD) reduction in excretion of prostacyclin (p less than 0.01). These data rule out a role for prostaglandins both in mediating dilation of large coronary arteries by nitrates and in affecting their vascular tone at rest.
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000652:urine; D000328:Adult; D000792:Angiography; D001241:Aspirin / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000187:drug effects*; D003331:Coronary Vessels / Q000187:drug effects; D005260:Female; D006801:Humans; D007548:Isosorbide Dinitrate / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009040:Motion Pictures; D011448:Prostaglandin Antagonists / Q000494:pharmacology; D011453:Prostaglandins / Q000502:physiology*; D014664:Vasodilation
chemical_list: D011448:Prostaglandin Antagonists; D011453:Prostaglandins; D015121:6-Ketoprostaglandin F1 alpha; D007548:Isosorbide Dinitrate; D001241:Aspirin