Role of prostaglandins in angiotensin II-induced gastric vasoconstriction.
The purpose of our study was to examine the role of prostaglandins in angiotensin II (ANG II)-induced gastric vasoconstriction. ANG II produced statistically significant, dose-related increases in vascular resistance of a mechanically perfused ex vivo stomach segment of chloralose-anesthetized dogs. We next examined the effect of cyclooxygenase inhibitors on responses to ANG II. Indomethacin (10 mg/kg), which blocked the vasodilator response to intra-arterial arachidonic acid, augmented the maximal increase in perfusion pressure during ANG II infusion. Similar results were found using a different cyclooxygenase inhibitor, meclofenamic acid. In the final experiments we used an enzyme immunoassay to measure 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) plasma concentrations. ANG II produced dose-related increases in gastric venous but not arterial levels of 6-keto-PGF1 alpha, the major metabolite of prostacyclin. Our results are consistent with the hypothesis that release of vasodilatory prostaglandins attenuates the vasoconstrictor response to ANG II in the gastric microcirculation.
Wood
J G
JG
Department of Surgery, University of Kansas Medical Center, Kansas City 66160.
Yan
Z Y
ZY
Cheung
L Y
LY
D015121:6-Ketoprostaglandin F1 alpha / Q000097:blood; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology; D001808:Blood Vessels / Q000187:drug effects; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008469:Meclofenamic Acid / Q000494:pharmacology; D011453:Prostaglandins / Q000502:physiology*; D013270:Stomach / Q000098:blood supply*; D014655:Vascular Resistance; D014661:Vasoconstriction / Q000502:physiology*
D011453:Prostaglandins; D000804:Angiotensin II; D016718:Arachidonic Acid; D008469:Meclofenamic Acid; D015121:6-Ketoprostaglandin F1 alpha; D007213:Indomethacin