INHIBITION OF EPINEPHRINE-EXACERBATED CORONARY THROMBUS FORMATION BY PROSTACYCLIN IN THE DOG

  • 1 January 1984
    • journal article
    • research article
    • Vol. 103  (2) , 204-214
Abstract
The effect of i.v. prostacyclin (PG[prostaglandin]I2) infusion on epinephrine exacerbation of platelet-mediated acute coronary thrombus formation in an in vivo canine model of coronary artery stenosis. Platelet thrombi form in mechanically stenosed dog circumflex coronary arteries, producing cyclical reductions in coronary blood flow (CRF) as measured with an electromagnetic flowmeter probe. Nine of 10 dogs exhibited spontaneously occurring CRF. With epinephrine (E) infusions of 10 .mu.g/min CRF frequency increased 64% (P < 0.025), CRF magnitude increased 27.1% (P < 0.05), and the rate of flow decline increased 112.8%, indicating that the rate of thrombus formation increased with E infusion (P < 0.005). When an identical E infusion was accompanied by simultaneous PGI2 infusion (150 ng/kg per min), CRF were abolished in 9 of 10 dogs and markedly inhibited in the other. After the 10 min of simultaneous E and PGI2 infusion, E infusion alone was continued. There was a recurrence of CRF within 2.49 .+-. 0.89 min after cessation of PGI2 infusion. CRF frequency in the subsequent 10 min was less than the frequency of CRF during the initial E infusion (P < 0.10) and not significantly different from that of the control period (no E infusion). The rate of flow decline and magnitude during the final E infusion after cessation of PGI2 infusion were not significantly different from those of the initial E infusion. PGI2 infusion in the coronary care unit may be potentially beneficial in cases of acute myocardial ischemia where elevated catecholamines are a thrombogenic stimulus.

This publication has 2 references indexed in Scilit: