Celiac artery in New Zealand rabbit: anatomical study of its origin and arrangement for experimental research and surgical practice Artéria celíaca em coelhos Nova Zelândia: estudo anatômico de sua origem e arranjo para a pesquisa experimental e a prática cirúrgica

Rabbits have been used as an experimental model in many diseases and for the study of toxicology, pharmacology and surgery in many universities. However, some aspects of their macro anatomy need a more detailed description, especially the abdominal and pelvic arterial vascular system, which has a huge variability in distribution and trajectory. Thirty cadaveric adult New Zealand rabbits, 13 male and 17 female, with an average weight and rostrum-sacral length of 2.5 kg and 40cm, respectively, were used. The thoracic aorta was cannulated and the vascular system was filled with stained latex S-65. The celiac artery and its proximal branches were dissected and lengthened in order to evidence origin and proximal ramifications. The celiac artery emerged between the 12th and 13th thoracic vertebra in 11 (36.7%) rabbits; at the level of the 13th thoracic vertebra in 6 (20%) rabbits; between the 13th thoracic vertebra and the 1st lumbar vertebra in 12 (40%) rabbits; and at the level of the 1st lumbar vertebra in only one (3.3%) rabbit. The mean length of the celiac artery was 0.5cm. The celiac artery first branch was the lienal artery, the second branch was the left gastric artery and the hepatic artery arose from the left gastric artery in all the dissected rabbits. No relation was observed between the celiac artery length and the rostrum-sacral length in rabbits. The number of left gastric and lienal artery branches and the distribution of celiac artery origin are not gender dependent.<br>Os coelhos têm sido usados como modelo experimental em diferentes patologias e para estudos de toxicologia, farmacologia e cirurgia em várias universidades. Entretanto apesar de sua grande utilização, muitos aspectos de sua macroanatomia, em especial os que se referem ao sistema vascular arterial que irrigam as viscerais abdomino-pélvicas ainda carecem de uma descrição mais detalhada, pois os vasos arteriais apresentam grande variabilidade na sua distribuição e trajeto. Foram utilizados 30 coelhos, 13 machos e 17 fêmeas, pesando em media 2,5 kg e apresentando comprimento rostro-sacral em torno de 40cm. A artéria aorta torácica foi canulada e através da mesma foi feita à fixação com solução de formaldeído a 10% e repleções vasculares com solução de Petrolátex S65 corado. A artéria celíaca e suas ramificações proximais foram dissecadas ao longo do seu percurso, registrando com auxílio de um paquímetro seu comprimento e sua esqueletopia. A artéria celíaca teve sua emergência de forma única diretamente da artéria aorta abdominal em todos os animais dissecados. Emitiu inicialmente a artéria lienal e a seguir a artéria gástrica esquerda que se continuou como hepática em todos os 30 animais. A artéria celíaca teve sua origem entre a 12ªe 13ª vértebra torácica em 11 animais (36,7 %), na 13ª vértebra torácica em 6 (20 %), entre a 13ª vértebra torácica e a 1ª vértebra lombar em 12 (40 %) e na 1ª vértebra lombar em apenas 1 animal (3,3%). O comprimento médio da artéria celíaca foi de 0,5cm. Não foi observada relação entre o comprimento da artéria celíaca e o comprimento rostro-sacral dos coelhos. O número de artérias gástricas esquerdas, ramificações principais da artéria lienal, bem como a origem da artéria celíaca independeram do sexo do animal

The maturation of vessels : a limitation to forced neovascularization?

Therapeutic angiogenesis is the induction of new blood vessels by the delivery of appropriate growth factors and is an attractive approach to the treatment of different ischemic conditions. The experience with initial clinical trials in the past decade has shown that this may be more complex than anticipated and highlights the need to incorporate current advancements in our understanding of the regulation of vessel growth in the design of novel strategies. The generation of new capillaries from neighboring microvasculature by angiogenesis can be represented as a two-step process: 1) tube formation, in which endothelial cells respond to gradients of angiogenic factors, proliferate and migrate towards areas where increased blood flow is needed, and 2) vascular maturation, in which pericytes are recruited to proliferating endothelium and induce quiescence and stabilization of the new capillaries through cell-cell contact and paracrine factors. The formation of a new vascular network with normal morphology and physiological function requires a proper balance between these two processes. Here we will review the current understanding of how the growth of normal or pathological blood vessels is determined by growth factor gradients in the microenvironment and what lessons can be learned to design more physiological strategies to achieve therapeutic angiogenesis for the treatment of ischemia. In particular, we will discuss the possibility to exploit vascular maturation as a target distinct from vessel induction, but capable of modulating the effects of angiogenic factors, and its implications for increasing safety and efficacy of therapeutic angiogenesis strategies