Morphometry of arterioles and capillaries in hearts of senescent mice.

OBJECTIVE

The aim was to characterise quantitative changes in the coronary arterioles and capillaries with aging in mice.

METHODS

Morphometric analysis of the coronary resistance vessels was carried out in 12 "young" mice (63 days) and 11 "old" mice (650 days).

RESULTS

Compared to hearts from young mice, those from senescent mice were heavier, contained less water, and differed in several variables characterising terminal vessels. The main changes were a decreased capillary and arteriolar density, increased heterogeneity of capillary spacing, and larger arterioles with thicker walls.

CONCLUSIONS

Aging of the murine myocardium is characterised by important changes at the level of the terminal vascular bed, the most prominent being a decrease in capillary and arteriolar density. The decrease in arteriolar density is most prominent in the classes of smallest vessels. All these changes represent an impairment of geometrical conditions for the oxygen supply to the myocardial tissue.