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Abstract Purpose: To investigate the protective effects of Polygonatum sibiricum polysaccharide (PSP) on acute heart failure (AHF) in rats. Methods: Sixty rats were randomly divided into control, model, and low-, middle- and high-dose PSP groups, 12 rats in each group. The low-, medium- and high-dose PSP groups were intragastrically administrated with 100, 200 and 400 mg/kg PSP for 5 days, respectively. On the sixth day, the AHF model was established by intraperitoneal injection of adriamycin. After 24h, the cardiac function, serum biochemical indexes, myocardial ATPase and succinate dehydrogenase levels and apoptosis related protein expressions were determined. Results: Compared with model group, in high-dose PSP group the heart rate, left ventricular systolic pressure, ±dp/dtmax, serum superoxide dismutase level, myocardial Na+-K+-ATPase, Ca2+-Mg2+-ATPase and succinate dehydrogenase levels and myocardial Bcl-2 and Caspase-3 protein expression levels were significantly increased (P<0.05), the left ventricular end diastolic pressure, serum cTnI, CK-MB, TNF-α, IL-6, malondialdehyde and nitric oxide levels and myocardial Bax and cleaved Caspase-3 protein expression levels were significantly decreased (P<0.05). Conclusions: Polysaccharide can prevent the acute heart failure induced by adriamycin. The mechanism may be related to its anti-oxidative stress, anti-inflammation and inhibition of cardiac myocyte apoptosis.

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Abstract Purpose: To evaluate the vascular ventilatory response in different stages of lung development and to compare them to the neonates with congenital diaphragmatic hernia (CDH) in a rabbit model. Methods: New Zealand rabbits were divided into 8 groups (n=5): E25, E27, E30, and CDH. All groups were ventilated on a FlexiVent (Scireq, Montreal, QC, Canada), compounding the other 4 groups. The CDH surgery was performed at E25 and the harvest at E30. Dynamic compliance (CRS), dynamic elastance (ERS) and dynamic resistance (RRS) were measured every 4 min/24 min. Median wall thickness (MWT) and airspace were measured. ANOVA Bonferroni tests were used to perform statistical analysis. Significance was considered when p<0.05. Results: CRS was higher in E30 compared to all other groups (p<0.05). CRS and RRS of CDH and E27 were similar and were higher in E25 (p<0.05). MWT was decreased according to the gestational age, was increased in E27V and E30V (p<0.05) and decreased in CDHV (p<0.05), airspace was decreased in E25 and increased in all ventilated groups (p<0.05). Conclusions: The ventilation response of congenital diaphragmatic hernia is like the pseudoglandular stage of the lung development. These findings add information about the physiology of pulmonary ventilation in CDH.

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Abstract Purpose: To investigate the role of the exogenous supply of adenosine triphosphate (ATP) in the expression of Bax and Bcl2L1 genes in intestinal ischemia and reperfusion (IR) in rats. Methods: The study was designed as a randomized controlled trial with a blinded assessment of the outcome. Eighteen adult male Wistar-EPM1 rats were housed under controlled temperature and light conditions (22-23°C, 12 h light/dark cycle). The animals were randomly divided into 3 groups: 1. Sham group (SG): no clamping of the superior mesenteric artery; 2. Ischemia and reperfusion group (IRG): 3. Ischemia and reperfusion plus ATP (IRG + ATP). ATP was injected in the femoral vein before and after ischemia. Afterwards, intestinal segments were appropriately removed and processed for Endothelial Cell Biology Rat RT2 Profiler PCR Array. Results: ATP promoted the upregulation of Bcl2L1 gene expression, whereas it did not have significant effects on Bax gene expression. In addition, the relation of Bax/Bcl2L1 gene expression in the IRG group was 1.39, whereas it was 0.43 in the IRG + ATP group. Bcl2L1 plays a crucial role in protecting against intestinal apoptosis after ischemia and reperfusion. Increased Bcl2L1 expression can inhibit apoptosis while decreased Bcl2L1 expression can trigger apoptosis. Conclusion: Adenosine triphosphate was associated with antiapoptotic effects on the rat intestine ischemia and reperfusion by upregulating of Bcl2L1 gene expression.

Resumo em Inglês:

Abstract Purpose: To investigate the apoptotic mechanisms in rabbits with blast-induced acute lung injury (ALI). Methods: A total of 40 rabbits were randomly divided into a blank control group (A, n=10) and an experimental group (EXP, n=30). Explosion-induced chest-ALI models were prepared and sampled at different time points (4, 12, and 24h after modeling, T1-T3) to test the lung dry weight/wet weight ratio (W/D) and arterial oxygen pressure (PaO2), apoptosis of lung tissue by the TUNEL assay, and Caspase-3, Bax, and Bcl-2 levels by immunohistochemical analysis. Furthermore, lung tissue was sampled to observe pathological morphology by microscopy. Results: Under a light microscope, Group EXP exhibited obvious edema in the pulmonary interstitial substance and alveoli, a large number of red blood cells, inflammatory cells, and serous exudation in the alveolar cavity, as well as thickening of the pulmonary interstitial fluid. Compared to Group A, the W/D ratio was significantly increased in Group EXP (P<0.01), while PaO2 was significantly reduced (P<0.01). The apoptosis index was significantly increased (P<0.01), and caspase-3 and Bax/Bcl-2 levels were increased (P<0.01). Conclusion: Apoptosis plays an important role in the occurrence and development of acute lung injury in rabbits by participating in lung injury and promoting the progression of ALI.

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Abstract Purpose: To quantify, through stereological and morphometric analysis, spermatogenesis in rats undergoing the natural aging process. Methods: Seventy-two male Wistar rats were divided into 6 equal groups according to age at the time of killing: 3, 6, 9, 12, 18, and 24 months. All the rats were subjected orchiectomy and collection of testicular parenchymal fragments for histological and morphometric analysis. The numerical density of spermatids was calculated using a stereological study, and morphometric analysis was conducted to measure the height of the germinal epithelium and the area of the seminiferous tubules. Results: We found that the 18 and 24 months groups showed a significant reduction in the number of round spermatids. However, the height of the germinal epithelium was not significantly different between the groups. The area of seminiferous tubules was also significantly reduced in the elderly rats compared to that in the young ones. Conclusion: Aging of rats showed a significant reduction in the number of round spermatids and the area of the seminiferous tubules, more pronounced in the rats at 18 and 24 months of life.

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Abstract Purpose: To evaluate the most frequent surgical techniques of high-risk colorectal anastomoses in rats. Methods: Wistar rats were enrolled in three different models comprising inflammatory (TNBS enema), vascular (portal vein occlusion) or obstructive (a non-ischemic constricting ring) mechanisms associated with colonic anastomosis that had accomplished after these former lesions. Histological analyses (Hematoxylin and eosin and Picrosirius red) were performed. Results: All anastomoses techniques were associated with risk factors and had complications, mainly anastomotic leakage. In Study 1, the use of a pharmacological agent, trinitrobenzene sulfonic acid (TNBS) mimicked an inflammatory bowel disease such as Crohn’s disease with 50% of anastomosis leakage, the higher percentage among all models tested. In Study 2, after portal ischemia followed by reperfusion it was observed a dense neutrophil infiltrate in the midst of necrotic tissue and fibrin at the anastomotic site and 5 days after the anastomosis, no collagen was produced. In Study 3, 5 days after the mechanical obstruction some denuded areas of epithelium with marked oedema of mucosa and submucosa were seen, at the anastomotic site and anastomosis group showed some reduction of collagen density when compared with Control/Sham group. Conclusion: All the experimental surgical techniques tested in rats were associated with high-risk colorectal anastomoses and were useful to study colonic anastomotic healing and intestinal leakage.

Resumo em Inglês:

Abstract Purpose: To develop a new 24 hour extended liver ischemia and reperfusion (LIR) model analyzing the late biochemical and histopathological results of the isolated and combined application of recognized hepatoprotective mechanisms. In addition, we used a new stratification with zoning to classify the histological lesion. Methods: A modified animal model of severe hepatic damage produced through 90 minutes of segmental ischemia (70% of the organ) and posterior observation for 24 hours of reperfusion, submitted to ischemic preconditioning (IPC) and topical hypothermia (TH) at 26ºC, in isolation or in combination, during the procedure. Data from intraoperative biometric parameters, besides of late biochemical markers and histopathological findings, both at 24 hours evolution time, were compared with control (C) and normothermic ischemia (NI) groups. Results: All groups were homogeneous with respect to intraoperative physiological parameters. There were no losses once the model was stablished. Animals subjected to NI and IPC had worse biochemical (gamma-glutamyl transpeptidase, alkaline phosphatase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, direct bilirubin, and total bilirubin) and histopathological scores (modified Suzuki score) compared to those of control groups and groups with isolated or associated TH (p < 0.05). Conclusion: The new extended model demonstrates liver ischemia and reperfusion at 24 hour of evolution and, in this extreme scenario, only the groups subjected to topical hypothermia, combined with ischemic preconditioning or alone, had better outcomes than those subjected to only ischemic preconditioning and normothermic ischemia, reaching similar biochemical and histopathological scores to those of the control group.

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Abstract Purpose: To investigate the impact of bone mesenchymal stem cells (BMSCs) intervention on the viscoelasticity of sciatic nerve in rats with chronic alcohol intoxication (CAI). Methods: The CAI rat models were prepared, divided into model groups, and treated with either BMSCs or basic fibroblast growth factor (bFGF). Then the rats underwent electrophysiological test and the serum levels of malondialdehyde (MDA), superoxide dismutase (SOD), and metallothionein (MT) were measured. Histological observation, stress relaxation test, and creep test were performed for the sciatic nerve of the CAI model in each group. Results: The MDA level of group BMSC was significantly lower (p<0.05) than that of groups MOD (the CIA model) and bFGF. The SOD and MT levels were higher in group BMSC than in groups MOD and bFGF (p<0.05). The motor nerve conduction velocity and amplitude were higher in group BMSC than in groups MOD and bFGF (p<0.05). The amounts of 7200s stress reduction and 7200 s strain increase of the sciatic nerve in group BMSC were greater than those in groups bFGF and MOD (p<0.05). Conclusion: Bone mesenchymal stem cells can improve the metabolism of free radicals, restore the tissue morphology and viscoelasticity of the chronic alcohol intoxication animal model, and positively affect the repairing of the injured sciatic nerve.