RESUMO
Considerando a escassez de informações na literatura, buscou-se traçar um perfil de formação da veia porta-hepática em 20 coelhos, reconhecendo o padrão de sua formação extraparenquimal e as possíveis relações entre os padrões de formação e distribuição da veia porta nesta espécie. Os animais foram injetados com látex Neoprene, fixados em formalina 10% e dissecados. A veia porta, na sua trajetória extraparenquimal, constituiu-se da junção da veia mesentérica cranial e caudal, recebendo ainda tributárias do estômago, baço e pâncreas. A veia mesentérica cranial formou-se, na totalidade dos casos a partir da confluência de um tronco jejunal e um tronco ileocecocólico. O tronco jejunal foi formado pela união de oito a dezoito veias jejunais e o tronco ileocecocólico constituiu-se a partir do encontro das veias cólicas, cecais e ileais, em diferentes arranjos e números. A veia mesentérica caudal foi formada pela união das veias retal e cólica esquerda.(AU)
Considering the shortage of information in the literature, it is looked for to draw a profile of formation of the portal vein in twenty rabbits, to recognize the distribution pattern, looking for evidences of possible correlation between the formation patterns and the distribution of the portal vein. The animaIs were injected by Neoprene latex, flxed in formalin 10% and dissected. The hepatic-portal vein, in it extraparenquimal trajectory, was constituted, for the junction of the cranial and caudal mesenteric veins and receives veins from the stomach, spleen and pancreas. The cranial mesenteric vein receives, in ali cases, a jejunal and an ileocecocolic trunk. The jejunal trunk was formed by the junction from eight to eighteen jejunal veins. The ileocecocolic trunk was formed by the encounter of the colic, cecals and ileal veins, in different arranjements and numbers. The caudal mesenteric vein was formed by junction of the rectal and left colic veins.(AU)
Assuntos
Animais , Coelhos , Veias Hepáticas/anatomia & histologia , Veias Hepáticas/metabolismo , Intestinos/anatomia & histologia , Intestinos/metabolismo , CoelhosRESUMO
Considerando a escassez de informações na literatura, buscou-se traçar um perfil de formação da veia porta-hepática em 20 coelhos, reconhecendo o padrão de sua formação extraparenquimal e as possíveis relações entre os padrões de formação e distribuição da veia porta nesta espécie. Os animais foram injetados com látex Neoprene, fixados em formalina 10% e dissecados. A veia porta, na sua trajetória extraparenquimal, constituiu-se da junção da veia mesentérica cranial e caudal, recebendo ainda tributárias do estômago, baço e pâncreas. A veia mesentérica cranial formou-se, na totalidade dos casos a partir da confluência de um tronco jejunal e um tronco ileocecocólico. O tronco jejunal foi formado pela união de oito a dezoito veias jejunais e o tronco ileocecocólico constituiu-se a partir do encontro das veias cólicas, cecais e ileais, em diferentes arranjos e números. A veia mesentérica caudal foi formada pela união das veias retal e cólica esquerda.
Considering the shortage of information in the literature, it is looked for to draw a profile of formation of the portal vein in twenty rabbits, to recognize the distribution pattern, looking for evidences of possible correlation between the formation patterns and the distribution of the portal vein. The animaIs were injected by Neoprene latex, flxed in formalin 10% and dissected. The hepatic-portal vein, in it extraparenquimal trajectory, was constituted, for the junction of the cranial and caudal mesenteric veins and receives veins from the stomach, spleen and pancreas. The cranial mesenteric vein receives, in ali cases, a jejunal and an ileocecocolic trunk. The jejunal trunk was formed by the junction from eight to eighteen jejunal veins. The ileocecocolic trunk was formed by the encounter of the colic, cecals and ileal veins, in different arranjements and numbers. The caudal mesenteric vein was formed by junction of the rectal and left colic veins.
Assuntos
Intestinos/anatomia & histologia , Intestinos/metabolismo , Coelhos , Veias Hepáticas/anatomia & histologia , Veias Hepáticas/metabolismoRESUMO
The heterogeneity of the liver parenchyma in relation to uric acid production from adenosine was investigated using the bivascularly perfused rat liver in the anterograde and retrograde modes. Adenosine was infused in livers from fed rats during 20 min at four different concentrations (20, 50, 100 and 200 microM) according to four experimental protocols as follows: (A) anterograde perfusion, with adenosine infusion into the portal vein; (B) anterograde perfusion, with adenosine in the hepatic artery, (C) retrograde perfusion, with adenosine in the hepatic vein; (D) retrograde perfusion, with adenosine in the hepatic artery. With protocols A, B, and D uric acid production from adenosine was always characterized by initial bursts followed by progressive decreases toward smaller steady-states. With protocol C the initial burst was present only when 200 microM adenosine was infused. The initial bursts in uric acid production were accompanied by simultaneous increases in the ratio of uric acid production/adenosine uptake rate. These initial bursts are thus representing increments in the production of uric acid that are not corresponded by similar increments in the metabolic uptake rates of adenosine. Global analysis of uric acid production revealed that the final steady-state rates were approximately equal for all infusion rates with protocols A, B and C, but smaller with protocol D. This difference, however, can be explained in terms of the differences in accessible cellular spaces, which are much smaller when protocol D is employed. When the analysis was performed in terms of the extra amounts of uric acid produced during the infusion of adenosine, where the initial bursts are also taken into account, different dose-response curves were found for each experimental protocol. These differences cannot be explained in terms of the accessible cell spaces and they are likely to reflect regional heterogeneities. From the various dose-response curves and from the known characteristics of the microcirculation of the rat liver it can be concluded that the initial bursts in uric acid production are generated in periportal hepatocytes. The reason for this heterogeneity could be related to the metabolic effects of adenosine, especially to oxygen uptake inhibition, which is likely to produce changes in the ATP/AMP ratios.