Late histological aspects of spleen autologous transplantation in rats

Abstract

Purpose:To evaluate macro and microscopically the late evolution of autotransplants of fragments of spleen in the greater omentum, mesenterium and peritoneal cavity, after 24 weeks of observation. Methods: Fifty two Wistar rats were used, males and adults, submitted to total splenectomy and divided in four groups. The group I -seventeen animals with implant of spleen fragment in the peritoneal cavity; group II -eighteen animals with implant in the omentum and group III -seventeen animals with implant fixed in mesenterium root. The group control (group IV) was formed by eight animals chosen aleatorily among the three groups. It was analyzed macro and microscopically the evolution of the implant, and in the histological study qualitative and quantitative criteria were adopted, with the counting of no cellular e cellular elements. Results: It was observed adherences to the adjacent tissues and vascularization in all of the fragments transplanted. The group I presented white pulp and preserved vascularization. In the group II were observed white pulp with follicular formations and lymphoid tissue preserved, and the red pulp in cordon aspect and hemorrhagic. In the group III were observed with depletion of white and red pulp, while others evidenced better preservation of the pulps. The counting of lymphocytes revealed significant difference between the groups I and IV and the group III and IV (p < 0.05). The counting of active macrophages revealed significant difference between the groups II and III (p < 0.05) and similarity between II and IV (p > 0.05). The other elements: active macrophages phagocyting hemosiderine, plasmocytes, fibroblasts, fibrocytes, giant cells, monocytes, interstitial spaces and fibers of collagen, did not show significant difference among the groups. Conclusions: The splenic autotransplantation is feasible, being the better place the greater omentum. This research demonstrated through qualitative and quantitative histological analysis that the splenic tissue autotransplanted in the omentum of Wistar rats preserves its function of defense of the organisms. Key words: Spleen. Transplantation, Autologous. Macrophages. Rats. RESUMO Objetivo:Avaliar macro e microscopicamente a evolução tardia do autotransplante de fragmentos de baço no grande epiplon, mesentério e cavidade peritoneal, após 24 semanas de observação. Métodos: Foram utilizados 52 ratos Wistar, machos e adultos, submetidos a esplenectomia total e divididos em quatro grupos. O grupo I -dezessete animais com implante de fragmento de baço solto na cavidade peritoneal; grupo II -dezoito animais com implante no grande epiplon e grupo III -dezessete animais com implante fixado na raiz do mesentério. O grupo controle (grupo IV) foi formado por oito animais escolhidos aleatoriamente entre os três grupos. Foram analisados macro e microscopicamente a evolução do implante, sendo que no estudo histológico foram adotados critérios qualitativos e quantitativos, com a contagem de elementos celulares e não celulares. Resultados: Foram observ...

Histological aspects of autologous transplantation of different fragments of the spleen in rats

“…The hemosiderin deposits in activated macrophages were also found in the work reported by Paredes et al 7 , Malago et al 8 ,…”

“…The regenerative process was more clearly observed in the group 25%, which showed the percentage of reduction of the group weighing less than 30%. This report highlights the fact Malago et al 8 proposes that the regenerative process delayed for thick implants, since the group 30% of the implanted fragments had a mean of 9mm. The study suggests that the fragments implanted with 8.17mm regeneration develop faster because the pulps, white and red, resembling the normal splenic tissue.…”

“…The fragments very thick undergoes degeneration occurs before the higher regeneration process, as to start the regeneration process areas have central necroses totally affected 8 .…”

Untitled

“…9 The implants should stay within the peritoneal cavity to allow for drainage to the portal vein. 11 The technique of allogenic implantation was adapted from the technique for autogenic implantation.…”

“…The data suggest that splenic implants achieve better function when they are located in sites with drainage to the portal vein. [9][10][11] There is evidence that implants in young animals regenerate better than those in adults. 7,9 Studies that had evaluated the induction of immunotolerance show that the spleen is capable of inducing immunotolerance after transplant in rodents.…”