1981 Volume 18 Issue 5 Pages 336-341
The purpose of this study is to determine the medial elastin and collagen content in injured aorta of strokeprone spontaneously hypertensive rats (SHRSP) developed by Okamoto and others as compared with normotensive contrast wistar-Kyoto rats (WKY). The thoratic aortae from 287 subjects aged from 36 to 622 days were obtained (44 WKY and 243 SHRSP). The elastin and collagen, which had been taken from the thoratic aortae, were measured using the microspectrophotometric procedure (MSP method). This method is selected because it is based on the fact that the maximum extinction of elastin, stained using Weigert stain, is 590nm and collagen, stained Van Gieson stain in 563nm respectively.
Results:
The elastin content in WKY group was 38 to 40V/V% and decreased slightly with aging. In the SHRSP group, the elastin content was 40V/V% or more before the age of 100 days, but decreased markedly after 100 days. At ages of over 200 days, the elastin content was distributed over a range of 20 to 30V/V%. After 200 days of age, the elastin decreased was from 60 to 68% in comparison with WKY group. The apoplexy group of SHRSP was also decreased about 78% in elastin content as compared with non-apoplexy group of SHRSP at ages from 150 to 350 days.
The collagen content in WKY group was 30 to 45%E at ages from 50 to 250 days and decreased slightly with aging at ages of 250 days. In the SHRSP group, the collagen was 40%E or more before the ages of 100 days and decreased straightly with aging from 50 to 350 days. There was another group in SHRSP, which was decreased from 42 to 30%E with ages from 300 to 600 days in collagen content.
So the progress of collagen with aging in SHRSP group was surely different from in WKY group. Moreover the collagen content in apoplexy group of SHRSP was decreased about 85% as compared with non-apoplexy group at ages from 150 to 350 days. The changes of elastin content was paralleled to collagen content (correlation coefficient 0.614) with any age in SHRSP.
It was proved that the elastic network and collagenous meshwork were destructed with decreasing elastin and collagen of aortic media in SHRSP group by hypertensive factor.
