title: Studies on the mechanism of the hypotensive action of SQ-14225, an angiotensin-converting enzyme inhibitor in anesthetized dogs.
abstract: Intravenous administration of SQ-14225, an angiotensin-converting enzyme inhibitor, to pentobarbital-anesthetized dogs resulted in significant decrease in the arterial blood pressure with no changes in the heart rate. Pressure-flow curves obtained in the perfused hind limb vasculature were shifted significantly to the right following SQ-14225 indicating a decrease in the hind limb vascular resistance. Neither the denervation of the hind limb nor bilateral nephrectomy prevented the decrease in the hind limb vascular resistance produced by SQ-14225 indicating that the vasodilator action of this agent was unrelated to either the sympathetic nervous system or the renal renin-angiotensin system. The reflex vasodilatation in the hind limb observed during the administration of pressor agents was significantly attenuated by SQ-14225. Similarly this agent also antagonized the reflex increases in the systemic blood pressure, hind limb perfusion pressure and heart rate observed during bilateral carotid occlusion. These results suggest that the hypotensive action of SQ-14225 in the pentobarbital-anesthetized dog may be unrelated to the renal renin-angiotensin system.
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors; D000818:Animals; D000959:Antihypertensive Agents; D001794:Blood Pressure / Q000187:drug effects; D002216:Captopril / Q000494:pharmacology*; D004285:Dogs; D006614:Hindlimb / Q000098:blood supply; D009392:Nephrectomy; D010424:Pentobarbital / Q000494:pharmacology; D011392:Proline / Q000031:analogs & derivatives*; D012039:Regional Blood Flow / Q000187:drug effects
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D011392:Proline; D002216:Captopril; D010424:Pentobarbital