Influence of elastin on rat small artery mechanical properties.
We have previously developed a method for estimating elastin content and organization in resistance arteries, where it is a minor component. The aim of the present study was to validate the method against a quantitative assay and to determine the relative importance of elastin content and organization for intrinsic elasticity of small arteries. Mesenteric third order branches (from 10-day-old, 1- and 6-month-old rats) and middle cerebral arteries (from 6-month-old rats) were pressurized. beta-Values were calculated from stress-strain relationships and used as indicators of intrinsic stiffness. The same pressure-fixed arteries were used to estimate elastin content and organization in the internal elastic lamina with confocal microscopy. Collagen and elastin contents were determined by Picrosirius Red staining and radioimmunoassay for desmosine, respectively. Confocal and desmosine assays gave similar results: no difference in elastin content of mesenteric vessels from 1- and 6-month-old rats, and a significant reduction in cerebral compared to mesenteric arteries. For all parameters (elastin and collagen content, fenestrae area and internal elastic lamina thickness) the best correlation was found between beta-values and fenestrae size. These data suggest that in small arteries: (1) confocal microscopy can be used as a method for the simultaneous study of changes in elastin content and organization; and (2) elastin organization might be a key determinant of intrinsic elastic properties.
González
José M
JM
Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma de Madrid, C/Arzobispo Morcillo 2, 28029-Madrid, Spain.
Briones
Ana M
AM
Starcher
Barry
B
Conde
M Victoria
MV
Somoza
Beatriz
B
Daly
Craig
C
Vila
Elisabet
E
McGrath
Ian
I
González
M Carmen
MC
Arribas
Silvia M
SM
D000375:Aging / Q000502:physiology; D000818:Animals; D001158:Arteries / Q000378:metabolism / Q000502:physiology*; D001391:Azo Compounds; D001696:Biomechanical Phenomena; D001794:Blood Pressure / Q000502:physiology; D003094:Collagen / Q000378:metabolism; D003895:Desmosine / Q000378:metabolism; D004548:Elasticity; D004549:Elastin / Q000502:physiology*; D005109:Extracellular Matrix / Q000378:metabolism; D008297:Male; D008638:Mesenteric Arteries / Q000378:metabolism / Q000502:physiology; D018613:Microscopy, Confocal; D020768:Middle Cerebral Artery / Q000378:metabolism / Q000502:physiology; D009213:Myography; D051381:Rats; D011921:Rats, Inbred WKY
D001391:Azo Compounds; D003895:Desmosine; C009798:C.I. direct red 80; D003094:Collagen; D004549:Elastin