Why the study?
Does hyaluronidase reduce ischaemic injury and alter blood flow or substrate exchange in a canine model of myocardial ischaemia?
Does hyaluronidase reduce ischaemic injury and alter blood flow or substrate exchange in a canine model of myocardial ischaemia?
In a canine model, hyaluronidase reduces myocardial ischemic injury by increasing collateral blood flow rather than altering metabolic substrate fluxes.
Hyaluronidase may reduce canine ischaemic injury via collateral flow; leaves open human translation and clinical testing.
The mechanism for reduced myocardial ischaemic injury by hyaluronidase was studied in open chest anaesthetized dogs. Repeated coronary artery occlusions were performed and the effect of hyaluronidase (225 NF units per kg) was studied during infusion of noradrenaline 0.125 mg/kg . min. Ischaemic injury was measured as the sum of ST-segment elevations (sigma ST) at 10-15 sites. Regional myocardial blood flow was determined by tracer microspheres. Blood for metabolic studies was sampled from a local coronary vein draining ischaemic tissue and from the coronary sinus draining predominantly non-ischaemic tissue. Hyaluronidase reduced sigma ST and increased subepicardial and transmural blood flow in ischaemic myocardium, but flow was not significantly changed in the ischaemic subendocardium or in non-ischaemic myocardium. Hyaluronidase had no significant effect on arterio-local venous differences of oxygen, glucose, lactate or free fatty acids across the ischaemic myocardium. In conclusion, reduction of myocardial ischaemic injury by hyaluronidase can be explained by increased collateral blood flow and not by an effect on fluxes of substrates across the ischaemic myocardium.
No takes yet. Share an insight, caveat, or question.
Smiseth et al. (1982) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: