A method for demonstrating the efficacy of interventions designed to limit infarct size following coronary occlusion: beneficial effect of hyaluronidase

Abstract

In order to measure the protective effect of interventions following coronary artery occlusions in dogs, the creatine kinase activity of myocardial tissue was assayed after 24 h and related to the myocardial blood flow of that tissue measured with ⁸⁵Sr labelled microspheres injected 15 min after occlusion. This assay showed normal levels when flow exceeded 50 cm³·min⁻¹·100 g⁻¹. In myocardium with flow reduced to 0 to 15 cm³·min⁻¹·100 g⁻¹, creatine kinase activity was 7.6 ± 0.6 IU·mg⁻¹ protein in control dogs and 13.1 ± 1.8 IU·mg⁻¹ protein (P−1 of hyaluronidase 20 min after occlusion. Where myocardial blood flow was reduced to 16 to 50cm³·min⁻¹·100 g⁻¹, creatine kinase activity was increased from 14.1 ± 1.1 to 20.5 ± 1.4 IU·mg⁻¹ protein by hyaluronidase. This method therefore assesses ischaemic damage independent of electrophysiological measurements and confirms myocardial preservation by hyaluronidase.