Aspectos morfológicos, morfométricos e ultraestruturais do baço de ratos após o clampeamento total do pedículo hepático

Abstract

RESUMOAvaliaram-se as alterações morfológicas, morfométricas e ultraestruturais que ocorreram no baço devido à isquemia produzida pelo clampeamento total do pedículo hepático. Para tanto, foram utilizados 40 ratos machos, distribuídos em quatro grupos de 10 animais. O grupo-controle (C) não foi submetido à isquemia, e os grupos tratados (E 1 , E 2 e E 3 ) foram submetidos ao clampeamento por 10, 20 e 30 minutos, respectivamente. Fragmentos do baço foram retirados e analisados histologicamente pela microscopia de luz (hematoxilina-eosina, ferrocianeto-férrico) e pela microscopia eletrônica de transmissão. Os resultados demonstraram que 10 minutos de clampeamento do pedículo hepático são suficientes para apresentar sinais de congestão esplênica e 20 e 30 minutos promovem intensa digestão de hemácias pelos macrófagos, com presença de grânulos de ferro (hemossiderina) no parênquima esplênico.Palavras-chave: rato, baço, clampeamento, pedículo hepático, hemossiderina ABSTRACTThe macro and microscopic alterations that occurred in the spleen during an ischemia produced by the hepatic pedicle total clamping were studied. Forty male rats were distributed in four groups of 10 animals each. The control group (C) was not submitted to ischemia and the treated groups (E 1 , E 2 , and E 3 ) were submitted to the clamping during 10, 20, and 30 minutes, respectively. Spleen fragments were collected and histologically analyzed by the light microscopy (eosin-hematoxilin and ferric ferrocyanide) and by the transmission electron microscopy. The results showed that 10 minutes of hepatic pedicle total clamping was enough produce signs of splenic congestion and 20 and 30 minutes promoted intense red bood cels digestion by the macrophages with the presence of iron granules (hemosiderin) in the splenic parenchyma.

Establishment of an experimental model of small intestinal ischemia and reperfusion injuries in New Zealand rabbits

“…Intestinal ischemia insult tolerance can also vary according to the different species. Experimental studies in rats and mice showed histopathological alterations in ischemic situations lasting for 30 minutes (Guimarães et al 2002, Freitas et al 2009a, 2009b; 45 minutes (Jiang et al 2011. ); 15 and 50 minutes (Guan et al 2009) and 60 minutes (Boybeyi et al 2014) whereas for dogs the ischemic time was 60 minutes (Chiu et al 1970), for rabbits starting at 60 minutes (Gao et al 2006) and horses starting at 70 minutes (Dabareiner et al 2001) and 120 minutes (Pagliosa et al 2009).…”

“…This obstruction involves occlusion of the cranial mesenteric artery (CMA) (Ritz et al 2005, Gao et al 2006, Santos et al 2008, Jiang et al 2011, Ben et al 2012, Boybeyi et al 2014 or the CMA and cranial mesenteric vein (Guimarães et al 2002, Tang et al 2010 or the extramural peri-intestinal marginal artery (PIMA) (Guan et al 2009). Some authors report that vascular clamping is the best method of ischemic applicability due to promoting the same occlusive situation in all animals and because of the similarity in clinical situations (Ribeiro & Yoshida 2005, Freitas et al 2009a, 2009b.…”