[Findings in myocardial extracellular matrix in fatal poisoning with addictive substances]

It have been reported that chronic drug abuse induces changes in extracellular matrix (ECM) composition of myocardium. Matrix metaloproteinases (MMP) play important role in ECM remodelling and alteration in the ECM of myocardium. They are able to cleave ECM components and may contribute to progression of heart damage. Remodelling implies an alteration in the ECM and in the spatial orientation of cells and intercellular components. In this report we evaluated the extracellular matrix of myocardium of deceased drug abusers and controls. The myocardium of 5 toxicologically positive cases and 4 control cases were analysed by zymography of MMP, electrophoresis of collagens and histologicaly. Gelatinases (MMP-2 and MMP-9) and collagenase (MMP-1) activities were increased in drug abusers compare to the controls. In contrast, alpha chain of collagen type I after 160 hours collagen extraction, were not observed in control specimens. The activation of MMP proenzymes is one of the critical steps that lead to ECM breakdown. Our findings suggest that the myocardial collagen matrix is damaged in drug abusers.