Effects of bradykinin preconditioning in an experimental intestinal ischemia reperfusion model on rats.

PURPOSE: To investigate the effects of bradykinin on reperfusion injury in an experimental intestinal ischemia reperfusion model. METHODS: We used 32 Wistar-Albino rats. We composed 4 groups each containing 8 rats. Rats in sham group were sacrified at 100 minutes observation after laparotomy. Thirty minutes reperfusion was performed following 50 minutes ischaemia in control group after observing 20 minutes. Ischaemic preconditioning was performed in one group of the study. We performed the other study group pharmacologic preconditioning by infusional administration of 10 µg/kg/minute bradykinin intravenously. We sacrified all of the rats by taking blood samples to evaluate the lactate and lactate dehydrogenase (LDH) after resection of jejunum for detecting tissue myeloperoxidase (MPO) activity. RESULTS: Lactate and LDH levels were significantly higher in control and study groups than the sham group (P<0.001). There is no difference between the study groups statistically. (P>0.05). The results were the same for MPO levels. Although definitive cell damage was determinated in the control group by hystopatological evaluation, the damage in the study groups observed was lower in different levels. However, there was no significant difference between the study groups statistically (P>0.05). CONCLUSION: Either ischeamic preconditioning or pharmacologic preconditioning made by bradykinin reduced the ischemia reperfusion injury at jejunum.

Characterization of the intestinal graft in a swine hypotensive after brain death model.

PURPOSE: To establish a hypotensive brain death pig model and observe the effects of hypotension on small bowel donors. METHODS: The hypotensive brain death model was produced using the modified intracranial water sac inflation method in ten domestic crossbred pigs. Effects of hypotensive brain death on small bowel tissue morphology were evaluated through changes in intestinal tissue pathology, tight junction protein of the intestinal mucosa and plasma intestinal fatty acid-binding protein (i-FABP) levels. The pathophysiological mechanism was examined based on changes in superior mesenteric artery (SMA) blood flow and systemic hemodynamics. RESULTS: After model establishment, SMA blood flow, and the mean arterial pressure (MAP) significantly decreased, while heart rate increased rapidly and fluctuated significantly. Small bowel tissue morphology and levels of tight junction protein of the intestinal mucosa showed that after model establishment, small bowel tissue injury was gradually aggravated over time (P<0.05). Plasma i-FABP levels significantly increased after brain death (P<0.05). CONCLUSIONS: A hypotensive brain death pig model was successfully established using an improved intracranial water sac inflation method. This method offers a possibility of describing the injury mechanisms more clearly during and after brain death.

Persistence of a vitelline artery on a Meckel's diverticulum as a cause of bowel infarction.

Meckel's diverticulum is a congenital anomaly, resulting from incomplete obliteration of the most proximal portion of the omphalomesenteric duct. It generally remains silent, but life-threatening complications may arise in 4-6% of the patients. We present a case of a 16-year-old male, who arrived at the emergency room with crampy abdominal pain, nausea, and vomiting, suggestive of acute appendicitis. Surgical exploration revealed 150 cm of infarcted small bowel, secondary to a mesodiverticular band of a Meckel's diverticulum at the site of obstruction. The ischemic small bowel with Meckel's diverticulum was resected, and an ileo-ileal anastomosis was carried out. The postoperative course was uneventful, and the patient was discharged on the fifth postoperative day. He was seen 12 months after his initial surgery, with a favorable outcome.

Characterization of the intestinal graft in a swine hypotensive after brain death model

Abstract Purpose: To establish a hypotensive brain death pig model and observe the effects of hypotension on small bowel donors. Methods: The hypotensive brain death model was produced using the modified intracranial water sac inflation method in ten domestic crossbred pigs. Effects of hypotensive brain death on small bowel tissue morphology were evaluated through changes in intestinal tissue pathology, tight junction protein of the intestinal mucosa and plasma intestinal fatty acid-binding protein (i-FABP) levels. The pathophysiological mechanism was examined based on changes in superior mesenteric artery (SMA) blood flow and systemic hemodynamics. Results: After model establishment, SMA blood flow, and the mean arterial pressure (MAP) significantly decreased, while heart rate increased rapidly and fluctuated significantly. Small bowel tissue morphology and levels of tight junction protein of the intestinal mucosa showed that after model establishment, small bowel tissue injury was gradually aggravated over time (P<0.05). Plasma i-FABP levels significantly increased after brain death (P<0.05). Conclusions: A hypotensive brain death pig model was successfully established using an improved intracranial water sac inflation method. This method offers a possibility of describing the injury mechanisms more clearly during and after brain death.

Small Bowel Bleeding: A Challenging Diagnosis.

The small intestine is an uncommon site for acute gastrointestinal (GI) bleeding. However, it is responsible for most cases in which the etiology of bleeding is not identified through endoscopy or colonoscopy. Despite great advances in technology, small bowel bleeding (SBB) is often a challenging diagnosis, requiring multiple blood transfusions, diagnostic procedures, and re-admissions. Consequently, it increases comorbidities, complications, and costs to the health care system. The presentation of SBB is diverse, and the etiology is dependent on the patient's age. It may require aggressive resuscitation and immediate bleeding-site localization for proper and successful care. The management is based on the etiology, the available technology, and physician expertise. We present a case of SBB in which multiple imaging and endoscopic procedures were required to identify the culprit lesion. Additionally, we review the most common etiologies, radiologic modalities, and endoscopic procedures available.

Diagnostic and therapeutic challenges of gastrointestinal angiodysplasias: A critical review and view points.

Gastrointestinal angiodysplasias (GIADs), also called angioectasias, are the most frequent vascular lesions. Its precise prevalence is unknown since most of them are asymptomatic. However, the incidence may be increasing since GIADs affect individuals aged more than 60 years and population life expectancy is globally increasing worldwide. They are responsible of about 5% to 10% of all gastrointestinal bleeding (GIB) cases. Most GIADs are placed in small bowel, where are the cause of 50 to 60% of obscure GIB diagnosed with video capsule endoscopy. They may be the cause of fatal severe bleeding episodes; nevertheless, recurrent overt or occult bleeding episodes requiring repeated expensive treatments and disturbing patient's quality-of-life are more frequently observed. Diagnosis and treatment of GIADs (particularly those placed in small bowel) are a great challenge due to insidious disease behavior, inaccessibility to affected sites and limitations of available diagnostic procedures. Hemorrhagic causality out of the actively bleeding lesions detected by diagnostic procedures may be difficult to establish. No treatment guidelines are currently available, so there is a high variability in the management of these patients. In this review, the epidemiology and pathophysiology of GIADs and the status in the diagnosis and treatment, with special emphasis on small bowel angiodysplasias based on multiple publications, are critically discussed. In addition, a classification of GIADs based on their endoscopic characteristics is proposed. Finally, some aspects that need to be clarified in future research studies are highlighted.

[Valor predictivo de la procalcitonina para la necesidad de cirugía y la presencia de isquemia y necrosis en pacientes con obstrucción del intestino delgado]. / Predictive value of procalcitonin for the need of surgery and the presence of ischemia and necrosis in patients with small bowel obstruction.

INTRODUCTION: The purpose of this prospective cohort study was to evaluate whether serum procalcitonin (PCT) levels predict the need for surgery and the presence of ischemia and/or necrosis (I/N) in small bowel obstruction. METHOD: Of 54 patients included, conservative management was performed in 31 (non-surgical group) and an exploratory laparotomy in 23 (surgical group). The reference value of the PCT was between 0.10 and 0.50 ng/mL. RESULTS: PCT levels were higher in the surgical group (7.05 ± 7.03 ng/mL) than in the non-surgical (0.37 ± 0.63 ng/mL), and in patients with I/N (10.06 ± 7.07 ng/mL) than without I/N (1.52 ± 1.45 ng/mL). In the ROC curve, the area under the curve was 0.91 for the need for surgery and 0.93 for I/N. PCT ≥ 0.80 ng/mL had the best sensitivity and specificity for surgery and ≥ 1.95 ng/mL for I/N. PCT was also an independent predictor for these events. CONCLUSIONS: The levels of PCT can recognize the need for surgery and the presence of I/N in small bowel obstruction. Additional studies are needed to affirm or invalidate our findings.

OBJETIVO: El propósito de este estudio de cohorte prospectivo fue evaluar si las concentraciones séricas de procalcitonina (PCT) predicen la necesidad de cirugía y la presencia de isquemia o necrosis (I/N) en la obstrucción del intestino delgado. MÉTODO: De 54 pacientes incluidos, se realizó manejo conservador en 31 (grupo no quirúrgico) y laparotomía exploradora en 23 (grupo quirúrgico). El valor de referencia de la PCT fue entre 0.10 y 0.50 ng/ml. RESULTADOS: Los valores de PCT fueron mayores en el grupo quirúrgico (7.05 ± 7.03 ng/ml) que en el no quirúrgico (0.37 ± 0.63 ng/ml), y en los pacientes con I/N (10.06 ± 7.07 ng/ml) que en aquellos sin I/N (1.52 ± 1.45 ng/ml). En la curva COR (Característica Operativa del Receptor), el área bajo la curva fue 0.91 para la necesidad de cirugía y 0.93 para la I/N. La PCT ≥ 0.80 ng/ml obtuvo las mejores sensibilidad y especificidad para una cirugía, y ≥ 1.95 ng/ml para I/N. La PCT también fue un predictor independiente para estos eventos. CONCLUSIONES: Los valores de PCT permiten reconocer la necesidad de cirugía y la presencia de I/N en la obstrucción del intestino delgado. Son necesarios estudios adicionales para reafirmar o invalidar nuestros hallazgos.

The role of ischemic preconditioning in gene expression related to inflammation in a rat model of intestinal ischemia-reperfusion injury

Abstract Purpose: To investigate the gene expression related to inflammation on mice subjected to intestinal ischemia and reperfusion (I/R) and treated with ischemic preconditioning (IPC). Methods: Thirty rats (EPM-Wistar), distributed in five groups of six animals each, were underwent anesthesia and laparotomy. The ischemia time was standardized in 60 minutes and the reperfusion time 120 minutes. IPC was standardized in 5 minutes of ischemia followed by 10 minutes of reperfusion accomplished before I/R. The control group was submitted only to anesthesia and laparotomy. The other groups were submitted to ischemia, I/R, ischemia + IPC and I/R + IPC. It was collected a small intestine sample to analyses by Quantitative Polymerase Chain Reaction in real Time (RT-qPCR) and histological analyses. It was studied 27 genes. Results: The groups that received IPC presented downregulation of genes, observed in of genes in IPC+ischemia group and IPC+I/R group. Data analysis by clusters showed upregulation in I/R group, however in IPC groups occurred downregulation of genes related to inflammation. Conclusion: The ischemia/reperfusion promoted upregulation of genes related to inflammation, while ischemic preconditioning promoted downregulation of these genes.

The role of atenolol in the modulation of the expression of genes encoding pro- (caspase-1) and anti- (Bcl2L1) apoptotic proteins in endothelial cells exposed to intestinal ischemia and reperfusion in rats

Abstract Purpose: To investigate the role of atenolol in the gene expression of caspase 1 (Casp1) and Bcl2L1 on vascular endothelium of rat intestine after ischemia and reperfusion (IR). Methods: Eighteen adult male Wistar rats were randomly divided into 3 groups (n=6): SG (Sham group): no clamping of the superior mesenteric artery; IRG: IR plus saline group: IRG+At: IR plus Atenolol group. Rats from IRG and IRG+At were subjected to 60 min of intestinal ischemia and 120 min of reperfusion. Atenolol (2mg/kg) or saline were injected in the femoral vein 5 min before ischemia, 5 min and 55 min after reperfusion. Thereafter, intestinal segments were appropriately removed and processed for Endothelial Cell Biology Rat RT2 Profiler PCR Array. Results: the anti-apoptotic Bcl2L1 gene expression was significantly down-regulated (-1.10) in the IRG and significantly up-regulated in the IRG+At (+14.15). Meanwhile, despite Casp1 gene expression was upregulated in both groups, it was significantly higher in the IRG (+35.06) than the IRG+At (+6.68). Conclusions: Atenolol presents antiapoptotic effects on rat intestine subjected to IR partly by the up-regulation of the anti-apoptotic Bcl2L1 gene expression. Moreover, atenolol can mitigate the pro-apoptotic and pro-inflammatory effects of Casp1 gene on rat intestine after IR.

The role of atenolol in the modulation of the expression of genes encoding pro- (caspase-1) and anti- (Bcl2L1) apoptotic proteins in endothelial cells exposed to intestinal ischemia and reperfusion in rats.

PURPOSE: To investigate the role of atenolol in the gene expression of caspase 1 (Casp1) and Bcl2L1 on vascular endothelium of rat intestine after ischemia and reperfusion (IR). METHODS: Eighteen adult male Wistar rats were randomly divided into 3 groups (n=6): SG (Sham group): no clamping of the superior mesenteric artery; IRG: IR plus saline group: IRG+At: IR plus Atenolol group. Rats from IRG and IRG+At were subjected to 60 min of intestinal ischemia and 120 min of reperfusion. Atenolol (2mg/kg) or saline were injected in the femoral vein 5 min before ischemia, 5 min and 55 min after reperfusion. Thereafter, intestinal segments were appropriately removed and processed for Endothelial Cell Biology Rat RT2 Profiler PCR Array. RESULTS: the anti-apoptotic Bcl2L1 gene expression was significantly down-regulated (-1.10) in the IRG and significantly up-regulated in the IRG+At (+14.15). Meanwhile, despite Casp1 gene expression was upregulated in both groups, it was significantly higher in the IRG (+35.06) than the IRG+At (+6.68). CONCLUSIONS: Atenolol presents antiapoptotic effects on rat intestine subjected to IR partly by the up-regulation of the anti-apoptotic Bcl2L1 gene expression. Moreover, atenolol can mitigate the pro-apoptotic and pro-inflammatory effects of Casp1 gene on rat intestine after IR.

The role of ischemic preconditioning in gene expression related to inflammation in a rat model of intestinal ischemia-reperfusion injury.

PURPOSE: To investigate the gene expression related to inflammation on mice subjected to intestinal ischemia and reperfusion (I/R) and treated with ischemic preconditioning (IPC). METHODS: Thirty rats (EPM-Wistar), distributed in five groups of six animals each, were underwent anesthesia and laparotomy. The ischemia time was standardized in 60 minutes and the reperfusion time 120 minutes. IPC was standardized in 5 minutes of ischemia followed by 10 minutes of reperfusion accomplished before I/R. The control group was submitted only to anesthesia and laparotomy. The other groups were submitted to ischemia, I/R, ischemia + IPC and I/R + IPC. It was collected a small intestine sample to analyses by Quantitative Polymerase Chain Reaction in real Time (RT-qPCR) and histological analyses. It was studied 27 genes. RESULTS: The groups that received IPC presented downregulation of genes, observed in of genes in IPC+ischemia group and IPC+I/R group. Data analysis by clusters showed upregulation in I/R group, however in IPC groups occurred downregulation of genes related to inflammation. CONCLUSION: The ischemia/reperfusion promoted upregulation of genes related to inflammation, while ischemic preconditioning promoted downregulation of these genes.

Remote ischemic preconditioning and tacrolimus in the fetal small bowel transplant in mice.

PURPOSE:: To evaluate the effect of remote ischemic preconditioning (IPC-R) in the fetal small bowel transplantation model. METHODS:: Two groups were constituted: The Isogenic transplant (ISO, C57BL/6 mice, n=24) and the allogenic transplant (ALO, BALB/c mice, n=24). In each group, the animals were distributed with and without IPC-R. It was obtained the following subgroups: Tx, IPC-R, Fk, IPC-Fk, in both strains. Intestinal grafts were stained with hematoxylin and eosin and immunohistochemically. RESULTS:: The graft development evaluation in ISO group showed that IPC-R reduced the development compared with ISO-Tx (5.2±0.4 vs 9.0±0.8) and IPC-R-Fk increased the graft development compared with IPC-R (11.2±0.7 and 10.2±0.8). In ALO group, IPC-Fk increased the development compared with ALO-Tx and ALO with IPC-R (6.0±0.8, 9.0±1.2, 0.0±0.0, 0.5±0.3). The PCNA expression was increased in ISO group treated with Fk and IPC-R compared to other groups (12.2±0.8 vs Tx: 8.8±0.9, IPC-R: 8.0±0.4 and Fk: 9.0±0.6). The graft rejection was lower in groups treated with IPC-R (-18%), Fk (-68%) or both (-61%) compared with ALO-Tx. CONCLUSION:: Remote ischemic preconditioning showed benefic effect even associate with Tacrolimus on the development and acute rejection of the fetal small bowel graft in the Isogenic and Allogenic transplants.

Remote ischemic preconditioning and tacrolimus in the fetal small bowel transplant in mice

ABSTRACT PURPOSE: To evaluate the effect of remote ischemic preconditioning (IPC-R) in the fetal small bowel transplantation model. METHODS: Two groups were constituted: The Isogenic transplant (ISO, C57BL/6 mice, n=24) and the allogenic transplant (ALO, BALB/c mice, n=24). In each group, the animals were distributed with and without IPC-R. It was obtained the following subgroups: Tx, IPC-R, Fk, IPC-Fk, in both strains. Intestinal grafts were stained with hematoxylin and eosin and immunohistochemically. RESULTS: The graft development evaluation in ISO group showed that IPC-R reduced the development compared with ISO-Tx (5.2±0.4 vs 9.0±0.8) and IPC-R-Fk increased the graft development compared with IPC-R (11.2±0.7 and 10.2±0.8). In ALO group, IPC-Fk increased the development compared with ALO-Tx and ALO with IPC-R (6.0±0.8, 9.0±1.2, 0.0±0.0, 0.5±0.3). The PCNA expression was increased in ISO group treated with Fk and IPC-R compared to other groups (12.2±0.8 vs Tx: 8.8±0.9, IPC-R: 8.0±0.4 and Fk: 9.0±0.6). The graft rejection was lower in groups treated with IPC-R (-18%), Fk (-68%) or both (-61%) compared with ALO-Tx. CONCLUSION: Remote ischemic preconditioning showed benefic effect even associate with Tacrolimus on the development and acute rejection of the fetal small bowel graft in the Isogenic and Allogenic transplants.

Brain caspase-3 and intestinal FABP responses in preterm and term rats submitted to birth asphyxia.

Neonatal asphyxia can cause irreversible injury of multiple organs resulting in hypoxic-ischemic encephalopathy and necrotizing enterocolitis (NEC). This injury is dependent on time, severity, and gestational age, once the preterm babies need ventilator support. Our aim was to assess the different brain and intestinal effects of ischemia and reperfusion in neonate rats after birth anoxia and mechanical ventilation. Preterm and term neonates were divided into 8 subgroups (n=12/group): 1) preterm control (PTC), 2) preterm ventilated (PTV), 3) preterm asphyxiated (PTA), 4) preterm asphyxiated and ventilated (PTAV), 5) term control (TC), 6) term ventilated (TV), 7) term asphyxiated (TA), and 8) term asphyxiated and ventilated (TAV). We measured body, brain, and intestine weights and respective ratios [(BW), (BrW), (IW), (BrW/BW) and (IW/BW)]. Histology analysis and damage grading were performed in the brain (cortex/hippocampus) and intestine (jejunum/ileum) tissues, as well as immunohistochemistry analysis for caspase-3 and intestinal fatty acid-binding protein (I-FABP). IW was lower in the TA than in the other terms (P<0.05), and the IW/BW ratio was lower in the TA than in the TAV (P<0.005). PTA, PTAV and TA presented high levels of brain damage. In histological intestinal analysis, PTAV and TAV had higher scores than the other groups. Caspase-3 was higher in PTAV (cortex) and TA (cortex/hippocampus) (P<0.005). I-FABP was higher in PTAV (P<0.005) and TA (ileum) (P<0.05). I-FABP expression was increased in PTAV subgroup (P<0.0001). Brain and intestinal responses in neonatal rats caused by neonatal asphyxia, with or without mechanical ventilation, varied with gestational age, with increased expression of caspase-3 and I-FABP biomarkers.

The influence of nicotine in healing of small bowel anastomoses in rats: angiogenesis and miofibroblasts.

OBJECTIVE: to know the effect of nicotine on angiogenesis and myofibroblast formation in anastomoses of the small bowel of rats. METHODS: we randomly divided 60 Wistar rats into the groups Nicotine (N) and control (C), according to the proposed treatment. Each group was subdivided into three subgroups according to the time interval used for the evaluation (7, 14 or 28 days). The N group with 30 animals received nicotine subcutaneously at a dose of 2mg/kg body weight, diluted in 0.3ml of 0.9% saline, twice daily for 28 days prior to the operation, and for more 7, 14 or 28 days, depending on the subgroup. The C group (also 30 animals) received only saline on the same conditions and time intervals. After 28 days we carried out an end-to-end anastomosis 10cm distal to the duodenojejunal flexure in each rat. After 7, 14 or 28 days after surgery, we euthanized ten animals of each group, sent specimens of the anastomosis areas, 1cm proximal to 1cm distal, to counting of blood vessels and myofibroblasts through immunohistochemical staining by the application of monoclonal anti-factor VIII antibodies and anti-smooth muscle alpha-actin. RESULTS: the administration of nicotine led to the decrease in the number of blood vessels measured on the 28th postoperative day and the number of myofibroblasts measured on the seventh day following completion of the anastomoses. CONCLUSION: administration of nicotine was deleterious on angiogenesis and myofibroblast formation in rats' small intestine anastomoses. OBJETIVO: conhecer o efeito da nicotina sobre a angiogênese e formação de miofibroblastos em anastomoses do intestino delgado de ratos. MÉTODOS: sessenta ratos Wistar foram divididos de maneira aleatória em grupos Nicotina(N) e Controle (C), conforme o tratamento proposto. Cada grupo foi subdividido em três subgrupos, de acordo com o intervalo de tempo utilizado para a avaliação (7, 14 ou 28 dias). O grupo N, com 30 animais, recebeu nicotina por via subcutânea, na dose de 2mg/Kg de peso, diluída em 0,3ml de solução salina a 0,9%, em duas aplicações diárias, durante 28 dias prévios à operação e por mais 7, 14 ou 28 dias, conforme o subgrupo. O grupo C (igualmente com 30 animais) recebeu somente a solução salina nas mesmas condições e intervalos de tempo. Após 28 dias efetuou-se, em cada rato, anastomose término-terminal a 10cm da flexura duodenojejunal. Após 7, 14 ou 28 dias da cirurgia, os dez animais de cada subgrupo foram eutanasiados, sendo que as áreas anastomosadas, 1cm proximal a 1cm distal, foram encaminhadas para contagem de vasos sanguíneos e miofibroblastos, através de coloração imuno-histoquímica por aplicação dos anticorpos monoclonais antifator VIII e anti-alfa-actina muscular lisa. RESULTADOS: a administração de nicotina levou à diminuição do número de vasos sanguíneos aferidos no 28o dia pós-operatório e do número de miofibroblastos aferidos no sétimo dia após a realização das anastomoses. CONCLUSÃO: a administração de nicotina foi deletéria sobre a angiogênese e formação de miofibroblastos em anastomoses do intestino delgado de ratos.

L-Arginine Modulates Intestinal Inflammation in Rats Submitted to Mesenteric Ischemia-Reperfusion Injury.

BACKGROUND: The goal of this study was to investigate whether exogenous offer of L-arginine (LARG) modulates the gene expression of intestinal dysfunction caused by ischemia and reperfusion. METHODS: Eighteen Wistar-EPM1 male rats (250-300 g) were anesthetized and subjected to laparotomy. The superior mesenteric vessels were exposed, and the rats were randomized into 3 groups (n = 6): the control group (CG), with no superior mesenteric artery interruption; the ischemia/reperfusion group (IRG), with 60 minutes of ischemia and 120 minutes of reperfusion and saline injections; and the L-arginine group (IRG + LARG), with L-arginine injected in the femoral vein 5 minutes before ischemia, 5 minutes after reperfusion, and after 55 minutes of reperfusion. The total RNA was extracted and purified from samples of the small intestine. The concentration of each total RNA sample was determined by using spectrophotometry. The first-strand complementary DNA (cDNA) was synthesized in equal amounts of cDNA and the Master Mix SYBR Green qPCR Mastermix (SABiosciences, a Qiagen Company, Frederick, Md). Amounts of cDNA and Master Mix SYBR Green qPCR Mastermix were distributed to each well of the polymerase chain reaction microarray plate containing the predispensed gene-specific primer sets for Bax and Bcl2. Each sample was evaluated in triplicate, and the Student t test was applied to validate the homogeneity of each gene expression reaction (P < .05). RESULTS: The gene expression of Bax in IRG (+1.48) was significantly higher than in IRG-LARG (+9.69); the expression of Bcl2L1 in IRG (+1.01) was significantly higher than IRG-LARG (+22.89). CONCLUSIONS: The apoptotic cell pathway of 2 protagonists showed that LARG improves the gene expression of anti-apoptotic Bcl2l1 (Bcl2-like 1) more than the pro-apoptotic Bax (Bcl2-associated X protein).

The influence of nicotine in healing of small bowel anastomoses in rats: angiogenesis and miofibroblasts / A influência da nicotina na cicatrização de anastomoses do intestino delgado em ratos: angiogênese e miofibroblastos

ABSTRACT Objective: to know the effect of nicotine on angiogenesis and myofibroblast formation in anastomoses of the small bowel of rats. Methods: we randomly divided 60 Wistar rats into the groups Nicotine (N) and control (C), according to the proposed treatment. Each group was subdivided into three subgroups according to the time interval used for the evaluation (7, 14 or 28 days). The N group with 30 animals received nicotine subcutaneously at a dose of 2mg/kg body weight, diluted in 0.3ml of 0.9% saline, twice daily for 28 days prior to the operation, and for more 7, 14 or 28 days, depending on the subgroup. The C group (also 30 animals) received only saline on the same conditions and time intervals. After 28 days we carried out an end-to-end anastomosis 10cm distal to the duodenojejunal flexure in each rat. After 7, 14 or 28 days after surgery, we euthanized ten animals of each group, sent specimens of the anastomosis areas, 1cm proximal to 1cm distal, to counting of blood vessels and myofibroblasts through immunohistochemical staining by the application of monoclonal anti-factor VIII antibodies and anti-smooth muscle alpha-actin. Results: the administration of nicotine led to the decrease in the number of blood vessels measured on the 28th postoperative day and the number of myofibroblasts measured on the seventh day following completion of the anastomoses. Conclusion: administration of nicotine was deleterious on angiogenesis and myofibroblast formation in rats' small intestine anastomoses.

RESUMO Objetivo: conhecer o efeito da nicotina sobre a angiogênese e formação de miofibroblastos em anastomoses do intestino delgado de ratos. Métodos: sessenta ratos Wistar foram divididos de maneira aleatória em grupos Nicotina(N) e Controle (C), conforme o tratamento proposto. Cada grupo foi subdividido em três subgrupos, de acordo com o intervalo de tempo utilizado para a avaliação (7, 14 ou 28 dias). O grupo N, com 30 animais, recebeu nicotina por via subcutânea, na dose de 2mg/Kg de peso, diluída em 0,3ml de solução salina a 0,9%, em duas aplicações diárias, durante 28 dias prévios à operação e por mais 7, 14 ou 28 dias, conforme o subgrupo. O grupo C (igualmente com 30 animais) recebeu somente a solução salina nas mesmas condições e intervalos de tempo. Após 28 dias efetuou-se, em cada rato, anastomose término-terminal a 10cm da flexura duodenojejunal. Após 7, 14 ou 28 dias da cirurgia, os dez animais de cada subgrupo foram eutanasiados, sendo que as áreas anastomosadas, 1cm proximal a 1cm distal, foram encaminhadas para contagem de vasos sanguíneos e miofibroblastos, através de coloração imuno-histoquímica por aplicação dos anticorpos monoclonais antifator VIII e anti-alfa-actina muscular lisa. Resultados: a administração de nicotina levou à diminuição do número de vasos sanguíneos aferidos no 28o dia pós-operatório e do número de miofibroblastos aferidos no sétimo dia após a realização das anastomoses. Conclusão: a administração de nicotina foi deletéria sobre a angiogênese e formação de miofibroblastos em anastomoses do intestino delgado de ratos.

Brain caspase-3 and intestinal FABP responses in preterm and term rats submitted to birth asphyxia

Neonatal asphyxia can cause irreversible injury of multiple organs resulting in hypoxic-ischemic encephalopathy and necrotizing enterocolitis (NEC). This injury is dependent on time, severity, and gestational age, once the preterm babies need ventilator support. Our aim was to assess the different brain and intestinal effects of ischemia and reperfusion in neonate rats after birth anoxia and mechanical ventilation. Preterm and term neonates were divided into 8 subgroups (n=12/group): 1) preterm control (PTC), 2) preterm ventilated (PTV), 3) preterm asphyxiated (PTA), 4) preterm asphyxiated and ventilated (PTAV), 5) term control (TC), 6) term ventilated (TV), 7) term asphyxiated (TA), and 8) term asphyxiated and ventilated (TAV). We measured body, brain, and intestine weights and respective ratios [(BW), (BrW), (IW), (BrW/BW) and (IW/BW)]. Histology analysis and damage grading were performed in the brain (cortex/hippocampus) and intestine (jejunum/ileum) tissues, as well as immunohistochemistry analysis for caspase-3 and intestinal fatty acid-binding protein (I-FABP). IW was lower in the TA than in the other terms (P<0.05), and the IW/BW ratio was lower in the TA than in the TAV (P<0.005). PTA, PTAV and TA presented high levels of brain damage. In histological intestinal analysis, PTAV and TAV had higher scores than the other groups. Caspase-3 was higher in PTAV (cortex) and TA (cortex/hippocampus) (P<0.005). I-FABP was higher in PTAV (P<0.005) and TA (ileum) (P<0.05). I-FABP expression was increased in PTAV subgroup (P<0.0001). Brain and intestinal responses in neonatal rats caused by neonatal asphyxia, with or without mechanical ventilation, varied with gestational age, with increased expression of caspase-3 and I-FABP biomarkers.