Arquitetura da parede vascular de segmentos torácico e abdominais da aorta de macaco prego (Cebus apella)

Abstract

O segmento torácico da aorta em macaco prego apresentou na túnica íntima uma lâmina elástica interna evidente, estando também presente em todos os segmentos aórticos abdominais analisados nesta espécie. A túnica média aórtica, ao nível torácico, mostrou uma quantidade média de 23,12 lâminas elásticas, tendo disposição circular e oblíqua em relação à luz vascular, e a túnica adventícia apareceu formada por fibras colágenas, dispostas irregularmente entre uma quantidade relativamente menor de fibras elásticas e de fibras musculares lisas. A túnica média do segmento abdominal aórtico, neste primata, observada ao nível supra-renal, apresentou em média 19,12 lâminas elásticas que apareceram relativamente desorganizadas e fragmentadas. Ao nível aórtico infra-renal, foram evidenciadas, na túnica média 11,75 lâminas elásticas, em média, e próximo da emissão das artérias ilíacas comuns a túnica média aórtica tinha cerca de 8,37 lâminas elásticas, as quais estavam entremeadas por fibras musculares lisas e por fibras colágenas que aparentavam aumentar a sua concentração próximo à adventícia. A lâmina elástica externa só foi visível no segmento abdominal aórtico mais distal, ou seja, próximo da emissão das artérias ilíacas comuns.

Structure and Histophysiological Considerations on the Arterial Wall of the Dog

“…1), such as was described in other mammal, also including the aorta of the dog (Viegas et al, 2001;Orsi et al;Mello et al, 2004Mello et al, , 2007Mello et al, , 2009. Inside the ascendant aortic wall a luminal blood flow was observed which shows a vortex pattern as a consequence of the left ventricular systolic pressure (Melbin & Detweiler, 1998).…”

“…1), similarly described in other mammals (Viegas et al, 2001;Mello et al, 2004Mello et al, , 2009, could be considered the radial distension verified in aortic wall during the impact of the systolic pressure of the heart left ventricle (Tindall & Svendsen;Sthebens, 1996). Apparently, the interrelations established among smooth muscle cells and connective lamellae and fibers were prevalent, mainly disposed as meshwork into the aortic medial and adventitial layers (Wolinsky & Glagov, 1967;Tindall & Svendsen;Clark & Glagov;Hass et al;Awal et al;Viegas et al, 2001;Orsi et al;Mello et al, 2004Mello et al, , 2007Mello et al, , 2009.…”

“…Similar pattern was described previously from the dog itself (Song & Roach); concerning the last histological pattern described, it was generally observed in mammals, according to the authors here cited. Nevertheless, it was necessary to consider from the aortic mural histology some species specific peculiarities, especially characterized in laboratory rodents (Mello et al, 2004); dog (Song & Roach; Orsi et al), and in tufted capuchin monkey (Mello et al, 2009).…”

“…the vertebral and external iliac arteries, presented a relative major number of smooth muscle cells in their parietal coats (Viegas et al, 2004;Martini et al, 2009;Tortora & Grabowisky, 2012). Perhaps, some papers suggested presence of a mixed structure from the abdominal part of aorta, in which equilibrium in the mural distribution of smooth muscle cells and connective matrix components were verified, with a minor number of elastic lamellae and fibers occurring (Viegas et al, 2001;Orsi et al, 2004;Mello et al, 2004Mello et al, , 2007Mello et al, , 2009). This last distal aortic wall composition apparently supports one of the causes for abdominal aortic aneurysm pathology (MacSweeney et al, 1992;Henney et al, 1993).…”

“…The predominance of aorta elastic tissue in mammals is accomplished by interconnections among elastic lamellae and connective dense lamellae throughout connective dense fibers. Complex networks were seen, including smooth muscle cells intermingled with elastic and connective dense lamellae and fibers, mainly disposed into the aortic medial layer structure (Tindall & Svendsen, 1982;Clark & Glagov, 1985;Hass et al, 1991;Awal et al, 1995;Viegas et al, 2001;Orsi et al;Mello et al, 2004Mello et al, , 2007Mello et al, , 2009). …”