Effect of phenoxybenzamine on indomethacin induced systemic vasoconstriction in dogs.
The effect of phenoxybenzamine (PBZ) on indomethacin (IM) induced systemic vasoconstriction was studied in 22 dogs using a right heart bypass procedure which allowed for control of cardiac output. Indomethacin alone (n = 8) caused an increase in mean arterial pressure (MAP) from 71 +/- 6.5 mmHg to 116 +/- 7.6 mmHg (p less than .05). In PBZ pretreated dogs (n = 8), the increase in MAP was from 49 +/- 3.4 mmHg to 80 +/- 6.8 mmHg (p less than .05). In 3 dogs given PBZ alone, MAP fell from 81 +/- 7.3 mmHg to 42 +/- 3.8 mmHg (p less than .05). In 3 untreated dogs, MAP fell from 86 +/- 4.1 mmHg to 63 +/- 9.0 mmHg. Thus, IM causes vasoconstriction in the systemic circulation of the dog, and this effects does not appear to be mediated by alpha adrenergic stimulation.
Anderson
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Kralios
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D000818:Animals; D004285:Dogs; D006439:Hemodynamics / Q000187:drug effects; D007213:Indomethacin / Q000494:pharmacology*; D010643:Phenoxybenzamine / Q000494:pharmacology*; D011453:Prostaglandins / Q000096:biosynthesis; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects*
D011453:Prostaglandins; D011942:Receptors, Adrenergic, alpha; D010643:Phenoxybenzamine; D007213:Indomethacin