Reduced Apoptosis in Newborn Compared to Adult Rat Intestine after Ischemia-Reperfusion Injury

Abstract

The pathogenesis of necrotizing enterocolitis (NEC) is unknown. Ischemia and reperfusion (I/R) injury has been considered to be a major contributing factor. More recent reports have noted that apoptosis is a significant and perhaps the principal contributor to cell death after I/R. Some reports revealed that infants with NEC and perforated bowel can completely recover with drainage alone. This study aims to assess the ability of newborn rat intestine to resist apoptosis after I/R injury compared with adult rat intestine. Intestines from 10 groups of rats (n = 6 for each study group) were studied: (1) normal control group; (2) ischemia group, receiving vascular occlusion for 60 min; (3) I/R groups receiving vascular occlusion for 60 min and reperfusion for 15, 30, and 60 min, respectively. Apoptosis was quantified by TUNEL methods. Statistical analysis was performed using ANOVA with Dunn’s test. TUNEL-positive cells per 10 crypts were significantly increased in the ischemia and I/R groups compared to the control group. The peak number of positive cells by TUNEL was recognized 30 min after reperfusion in adult and newborn rats and then reduced gradually. The newborn rats had significantly less TUNEL-positive cells per 10 crypts than adult rats subjected to I/R injury (p < 0.05). We demonstrated that the activation of apoptosis occurred after intestinal I/R injury, especially during the reperfusion phase. The newborn intestine was more resistant to I/R injury and thus may have significant clinical application.

Apoptosis of interstitial cells of Cajal, smooth muscle cells, and enteric neurons induced by intestinal ischemia and reperfusion injury in adult guinea pigs

“…Cells were also present after double labeling (arrows) with α-SMA (red) and TUNEL (green; d-f). Scale bar a refers to all panels to the liver [21], kidney [22], heart [28], and lung [24], as well as intestine [23], apoptosis is often present in the tissues. We have confirmed these previous results showing cell death by using TUNEL methodology and about 10-15% of the apoptotic Kit+ cells are at an early stage after I/R.…”

“…Other studies have also shown the loss of Kit immunopositivity after intestinal surgical manipulation [18] and gastrointestinal disorders, such as intestinal obstruction [19,20], and this loss is probably one of the underlying mechanisms associated with intestinal motility dysfunction. However, it is noteworthy that apoptosis is generally observed in the liver [21], kidney [22], intestine [23], and lung [24] after I/R injuries, but it is not clear whether apoptosis of the ICC, smooth muscle cells (SMC), or enteric neurons is also involved in the intestinal I/R injury. Furthermore, a reexpression of Kit protein may contribute to the recovery of ICC networks after disrupted by intestinal disorders [18][19][20].…”

Oral arginine improves intestinal recovery following ischemia-reperfusion injury in rat

“…Recent evidence has shown that ischemia and/or IR induces apoptosis in several tissues, such as the brain and the liver. Recently an effect of IR on apoptosis of enterocytes in intestine has been demonstrated [6,12].…”

Apoptose no cólon menor eqüino submetido à isquemia e reperfusão experimentais

“…No entanto, a técnica de TUNEL quando utilizada na maioria das vezes serviu apenas para avaliação qualitativa da apoptose (Noda et al 1998, Ykeda et al 1998, Cheng & Tam 2000, Azuara et al 2004, Hosaka et al 2005. Entretanto, como neste trabalho, também já foi utilizada a técnica de TUNEL para um estudo quantitativo do número de células apoptóticas por campo histoló-gico (Rowe et al 2003, Hung et al 2004, Luo et al 2004.…”