[Early histochemical aging of arteries submitted to constant physical stress]

The hemodynamic stress effect on the tissue metabolism of coronary and splenic arteries was histochemically and comparatively studied in beagle dogs 6 months, 1 and 8 years-old. The results indicated that more than 30 enzyme activities (EA) studied are similar in both vessels in the young animal (6 months). During ageing (1--8 years old dogs) the EA linked to aerobic oxydo-reduction, ATP hydrolysis and estero-lipolysis decreased in the coronary arterial wall; conjointly the lysosomal acid phosphatase increased. Splenic artery EA remained unchanged during this period. These data suggest that repeated hemodynamic injuries may accelerate aging of the coronary artery by early perturbations of EA linked to oxydoreduction and to lipolytic power of the arterial smooth muscle cells.