Effects of Exercise and Anemia on Coronary Arteries of Small Animals as Revealed by the Corrosion-Cast Technique

Vinyl acetate corrosion casts were prepared of the coronary arterial trees of chronically exercised rats and of suitable control animals. In four experiments, there was a statistically significant increase in the mean coronary-cast weight of the exercised animals over that of controls. In two experiments, the coronary- cast/heart-weight ratios were significantly increased. In three-week-old ducklings rendered anemic by an iron-deficient diet, corrosion casts of the coronary vessels showed marked increases in cast weight, increase in size of homologous vessels, and generally more luxuriant arborization of the tree. No differences were found when coronary casts of thyroxin-injected or of pentaerythritol tetranitrate-injected rats were compared with those of control animals. Right-to-left-side coronary anastomoses were demonstrated in 75 per cent of guinea-pig hearts studied by the corrosion-cast technique. In five experiments, retrograde filling of a ligated anterior descending branch of the left coronary artery was demonstrated when the vinyl acetate solution was injected into the aorta.