Quantitative analysis of microstructural components of human cerebral arteries.

Microstructural components were analyzed quantitatively by means of a microphotometric technique applied to three kinds of major cerebral arteries and two kinds of extracranial arteries of comparable size obtained from human autopsy subjects. No statistically significant difference was found in the fractions of three structural components, elastin (Fe), collagen (Fc), and smooth muscle (Fm), in the total of fractions of these three components and in the ratio between extracranial arteries. The Fe-values were significantly less in cerebral arteries than in extracranial arteries. The Fc/Fe ratios in cerebral arteries were about triple those in extracranial arteries. Although there was no statistically significant difference in the Fe- and the Fm-values between the two age groups, under 49 and over 50 years old, the Fc/Fe ratio were higher in the older age group. This change of microstructural composition with age was more prominent in cerebral arteries than in extracranial arteries.