technetium-tc-99m-sulfur-colloid and Coronary-Thrombosis

The authors employed a canine model of coronary thrombosis, induced by injection of radioactive blood clot, via a catheter placed in the left anterior descending (LAD) coronary artery, to compare effects of different rates of administration of recombinant tissue plasminogen activator (rtPA) on efficacy of coronary thrombolysis. In one group of dogs 0.75 mg/kg of rtPA was administered via the catheter placed in the LAD coronary artery over fifteen minutes. In a second group of dogs the same dose of rtPA was administered over forty-five minutes. Compared with the group in which the drug was administered over forty-five minutes, by thirty and forty-five minutes after onset of treatment, the extent of coronary thrombolysis was significantly greater (P < 0.05) in the group who received the drug over fifteen minutes. These results demonstrate that the rate of intracoronary administration of rtPA may significantly affect thrombolytic efficacy.

Topics: Animals; Catheterization; Coronary Thrombosis; Coronary Vessels; Dogs; Infusions, Intra-Arterial; Radionuclide Imaging; Recombinant Proteins; Technetium Tc 99m Sulfur Colloid; Thrombolytic Therapy; Time Factors; Tissue Plasminogen Activator

We employed a canine model of coronary thrombosis, induced by injection of radioactive blood clot, via a catheter placed in the left anterior descending coronary artery, to compare effects of intracoronary administration of recombinant tissue plasminogen activator (rtPA) and urokinase (UK) on rate and extent of coronary thrombolysis. Two doses of UK, 15,000 U/kg (UK15) and 30,000 U/kg (UK30) and two doses of rtPA, 0.25 mg/kg (rtPA.25) and 0.75 mg/kg (rtPA.75) were given. Drugs were infused over 45 min. Compared with the other regimens, rate and extent of coronary thrombolysis were significantly increased with rtPA.75. Also, despite a much higher dose of UK, coronary thrombolysis was similar with UK30 and rtPA.25. Compared with UK15, rate and extent of coronary thrombolysis were increased with rtPA.25. These results indicate that intracoronary administration of rtPA is superior to intracoronary UK in inducing thrombolysis.

Topics: Animals; Coronary Thrombosis; Coronary Vessels; Disease Models, Animal; Dogs; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Gamma Cameras; Infusions, Intra-Arterial; Radionuclide Imaging; Recombinant Proteins; Technetium Tc 99m Sulfur Colloid; Thrombolytic Therapy; Time Factors; Tissue Plasminogen Activator; Urokinase-Type Plasminogen Activator