FUNCTIONAL-MORPHOLOGY OF LAMININ, COLLAGEN TYPE-IV, COLLAGEN BUNDLES,ELASTIN, AND PROTEOGLYCANS IN THE BULBUS-ARTERIOSUS OF THE WHITE BASS, MORONE-CHRYSOPS (RAFINESQUE)
Ds. Raso, FUNCTIONAL-MORPHOLOGY OF LAMININ, COLLAGEN TYPE-IV, COLLAGEN BUNDLES,ELASTIN, AND PROTEOGLYCANS IN THE BULBUS-ARTERIOSUS OF THE WHITE BASS, MORONE-CHRYSOPS (RAFINESQUE), Canadian journal of zoology, 71(5), 1993, pp. 947-952
Immunolocalization of the basal lamina proteins laminin and collagen t
ype IV, and the distribution of collagen bundles, elastin fibres, and
proteoglycans in the bulbus arteriosus of adult white bass, Morone ch
sops, were investigated. The bulbus arteriosus consists of three disce
rnible layers: intima, media, and adventitia. The media composes appro
ximately 95 % of the bulbus arteriosus volume, and consists of elastin
fibres, which allow distensibility, and proteoglycans which may be ut
ilized in dissipating the frictional forces in an actively expanding b
ulbus arteriosus. Laminin and collagen type IV were co-localized to th
e luminal and bulbar-ventricular valve subendothelium anchoring the en
dothelium to the underlying parenchyma. Laminin and collagen IV were a
lso expressed in the adventitia along with prominent collagen bundles
which may serve to limit the expansion of the bulbus arteriosus at hig
h intraluminal pressures. Collagen bundles and scattered elastin fibre
s are longitudinally aligned along the ventricular border of the bulba
r-ventricular valve, acting as a semi-stiff border facilitating the ti
mely opening of the valve and buffering the systolic force of inflowin
g blood. Proteoglycans occupy the bulbar portion of the valve and are
most probably involved in absorbing the initial recoil from the front
of the valve, thereby decreasing wear and tear upon the valve.