[Hemodynamic mechanisms of the hypotensive action of the new calcium antagonist foridon in acute hypertension in rabbits. A comparison with nifedipine].
The radioactive microsphere technique was used to study hemodynamic mechanisms of action of 2 calcium antagonists--foridon and nifedipine in conscious rabbits with acute hypertension evoked by immobilization. Microspheres were injected before and 5 min after bolus i.v. injection of equihypotensive (10% blood pressure drop) doses of nifedipine (30 mcg/kg) and foridon (50 mcg/kg). Nifedipine in most cases decreased cardiac index by 7% without significant changes in regional hemodynamic. After foridon injection total peripheral resistance decreased by 19% (P less than 0.05) and cardiac index increased by 18%. There were increase in blood flow: in the heart by 34% (P less than 0.05), in the skeletal muscle by 41% (P less than 0.05) and in testes by 12% (P less than 0.05). The results show that in acute stress-induced hypertension these dihydropyridine-derivatives have different hemodynamic mechanisms of action: nifedipine preferentially depress myocardial contractility, whereas foridon dilates blood vessels.
D000208:Acute Disease; D000818:Animals; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D004353:Drug Evaluation, Preclinical; D006439:Hemodynamics / Q000187:drug effects*; D006973:Hypertension / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D007275:Injections, Intravenous; D008297:Male; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D011817:Rabbits; D012149:Restraint, Physical
D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D009543:Nifedipine; C045912:ryodipine
Gemodinamicheskie mekhanizmy gipotenzivnogo deĭstviia novogo antagonista kal'tsiia foridona pri ostroĭ gipertonii u krolikov. Sravenie s nifedipinom.