Determination of the optical density of human coronary arterial walls

Conclusions

1. The greatest thickness is found for the segment of a coronary artery adjacent to the myocardium; this effect is observed even in a neonate.

2. At a young age, the greatest thickness is found for the middle and outer wall layers of both coronary arteries.

3. In individuals reaching age 40 and having atherosclerosis of the major branches of the cardiac arteries, the walls of both coronary arteries become thicker due to the inner and middle layers, but the thickening of the individual layers is most pronounced in the wall of the left coronary artery.

4. The method of optical densitometry relative to stained histological sections of the vascular wall may be used for the relative determination of the densities of tissues and their distributions over the individual wall layers.

5. The optical density of elastic tissue of the walls of the coronary arteries reaches a maximum in the third decade of life in the human and decreases after age 40 (especially in the distal segment of the left coronary artery).

6. The optical density of the total connective tissue in the walls of the left coronary artery increases with increasing age, especially in the distal segment of this artery. In youth, the optical density of connective tissue is greater in the wall of the right coronary artery, but with increasing age this density decreases markedly.