STUDIES ON THE MECHANISM OF THE HYPOTENSIVE ACTION OF SQ-14225, AN ANGIOTENSIN-CONVERTING ENZYME-INHIBITOR IN ANESTHETIZED DOGS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 25  (3) , 429-446
Abstract
I.v. administration of SQ-14225 [D-3-mercapto-2 methylpropanoyl-L-proline], 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 pressor agent administration was significantly attenuated by SQ-14425. 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. The hypotensive action of SQ-14225 in the pentobarbital-anesthetized dog may be unrelated to the renal renin-angiotensin system.