Comparative studies on the extractability of collagen from aortas of stroke-prone spontaneously hypertensive and normotensive rats.
The molecular states of collagen in the aortas of age-matched stroke-prone spontaneously hypertensive (SHRSP) and normotensive Wistar Kyoto rats (WKY) were studied by analyzing its extractability under defined conditions. The monomeric and oligomeric collagen extractable with 0.5 M acetic acid/6 M urea from aortic homogenates of 9-month-old SHRSP and WKY comprised approx. 0.6 and 2.0%, respectively, of the total collagen. On incubation of the acetic acid/urea-extracted residues with pepsin at 4 degrees C, the levels of the collagen alpha 1(I) and alpha 2(I) chains solubilized from the SHRSP residues were both less than 50% of those from the WKY residues. When the residues were incubated with pepsin at 15 or 25 degrees C, the differences became smaller. When the acetic acid/urea residues were hydrolyzed with cyanogen bromide, nearly identical peptide maps were obtained for SHRSP and WKY. The aortas from 2-month-old SHRSP and WKY contained much larger proportions of acid/urea-extractable collagen than those of the older rats (8.2 and 13% of the respective total collagen). The levels of the alpha 1(I) and alpha 2(I) chains solubilizable from the respective residues by pepsin at 4 degrees C were similar to each other. These results indicate that aortic collagen fibrils in SHRSP are stiffened more prominently than those in WKY.
Matsumura
S
S
Department of Biochemistry, Saga Medical School, Japan.
Higashino
H
H
Takashima
T
T
Ikeda
N
N
Fujitani
N
N
Muguruma
M
M
D000375:Aging; D000818:Animals; D001012:Aorta, Abdominal / Q000737:chemistry*; D001013:Aorta, Thoracic / Q000737:chemistry*; D002561:Cerebrovascular Disorders / Q000378:metabolism*; D003094:Collagen / Q000302:isolation & purification*; D003488:Cyanogen Bromide; D008297:Male; D010434:Pepsin A; D011487:Protein Conformation; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013045:Species Specificity; D013050:Spectrometry, Fluorescence
D003094:Collagen; D010434:Pepsin A; D003488:Cyanogen Bromide