1. The chemical characteristics of the vascular connective tissue components were determined in stroke-prone (SP), stroke-resistant (SR) spontaneously hypertensive (SH) rats and normotensive Wistar-Kyoto (WK) rats.
2. The ratio of hydroxylysine to hydroxylysine plus lysine in the vascular collagen was increased in 6-month-old SP—SH rats and SR—SH rats as compared with WK rats.
3. An age-related increase in uronic acid and hexose content of the aorta was noted in SP—SH, SR—SH and WK rats. However, the increase was more prominent in SH rats, especially SP—SH rats at the stages examined (11 weeks and over 8 months of age).
4. The ratio of galactosyl-hydroxylysine to glucosyl-galactosyl-hydroxylysine in the aortic collagen was decreased in 6-month-old SH rats, especially SP—SH rats as compared with WK rats.
5. A relative increase in β and γ components in aortic collagen was noted in 6-month-old SP—SH rats when compared with SR—SH rats.
6. The increased content of uronic acid and hexose and the structural changes of vascular collagen as demonstrated in SP—SH rats might be releated to the fragility of the arterial wall and/or to the pathogenesis of stroke-proneness.